diff --git a/cumulus/pallets/parachain-system/src/block_weight/mock.rs b/cumulus/pallets/parachain-system/src/block_weight/mock.rs
index 7dba292f55de3..8b2a738f26dc2 100644
--- a/cumulus/pallets/parachain-system/src/block_weight/mock.rs
+++ b/cumulus/pallets/parachain-system/src/block_weight/mock.rs
@@ -194,6 +194,7 @@ pub mod test_pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> sp_runtime::traits::ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/polkadot/runtime/common/src/claims/benchmarking.rs b/polkadot/runtime/common/src/claims/benchmarking.rs
index f9150f7980e50..93fc24c72e085 100644
--- a/polkadot/runtime/common/src/claims/benchmarking.rs
+++ b/polkadot/runtime/common/src/claims/benchmarking.rs
@@ -26,10 +26,7 @@ use frame_support::{
 };
 use frame_system::RawOrigin;
 use secp_utils::*;
-use sp_runtime::{
-	traits::{DispatchTransaction, ValidateUnsigned},
-	DispatchResult,
-};
+use sp_runtime::{traits::DispatchTransaction, DispatchResult};
 
 const SEED: u32 = 0;
 
@@ -74,6 +71,9 @@ fn create_claim_attest<T: Config>(input: u32) -> DispatchResult {
 mod benchmarks {
 	use super::*;
 
+	#[allow(deprecated)]
+	use sp_runtime::traits::ValidateUnsigned;
+
 	// Benchmark `claim` including `validate_unsigned` logic.
 	#[benchmark]
 	fn claim() -> Result<(), BenchmarkError> {
@@ -104,6 +104,7 @@ mod benchmarks {
 		{
 			let call = <Call<T> as Decode>::decode(&mut &*call_enc)
 				.expect("call is encoded above, encoding must be correct");
+			#[allow(deprecated)]
 			super::Pallet::<T>::validate_unsigned(source, &call)
 				.map_err(|e| -> &'static str { e.into() })?;
 			call.dispatch_bypass_filter(RawOrigin::None.into())?;
@@ -168,6 +169,7 @@ mod benchmarks {
 		{
 			let call = <Call<T> as Decode>::decode(&mut &*call_enc)
 				.expect("call is encoded above, encoding must be correct");
+			#[allow(deprecated)]
 			super::Pallet::<T>::validate_unsigned(source, &call)
 				.map_err(|e| -> &'static str { e.into() })?;
 			call.dispatch_bypass_filter(RawOrigin::None.into())?;
diff --git a/polkadot/runtime/common/src/claims/mod.rs b/polkadot/runtime/common/src/claims/mod.rs
index 234939da42110..eb7a29184b8aa 100644
--- a/polkadot/runtime/common/src/claims/mod.rs
+++ b/polkadot/runtime/common/src/claims/mod.rs
@@ -496,6 +496,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/polkadot/runtime/common/src/claims/tests.rs b/polkadot/runtime/common/src/claims/tests.rs
index dff2623cb9342..b420081d0568c 100644
--- a/polkadot/runtime/common/src/claims/tests.rs
+++ b/polkadot/runtime/common/src/claims/tests.rs
@@ -564,6 +564,7 @@ fn real_eth_sig_works() {
 }
 
 #[test]
+#[allow(deprecated)]
 fn validate_unsigned_works() {
 	use sp_runtime::traits::ValidateUnsigned;
 	let source = sp_runtime::transaction_validity::TransactionSource::External;
diff --git a/polkadot/runtime/parachains/src/disputes/slashing.rs b/polkadot/runtime/parachains/src/disputes/slashing.rs
index a750ac7750e3a..a24b754635446 100644
--- a/polkadot/runtime/parachains/src/disputes/slashing.rs
+++ b/polkadot/runtime/parachains/src/disputes/slashing.rs
@@ -531,6 +531,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/polkadot/runtime/parachains/src/paras/mod.rs b/polkadot/runtime/parachains/src/paras/mod.rs
index 4ffdb98dcdb87..b8a2d4097af4b 100644
--- a/polkadot/runtime/parachains/src/paras/mod.rs
+++ b/polkadot/runtime/parachains/src/paras/mod.rs
@@ -1365,6 +1365,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/polkadot/runtime/parachains/src/paras/tests.rs b/polkadot/runtime/parachains/src/paras/tests.rs
index 04b7c1a1f6734..1facdd498e405 100644
--- a/polkadot/runtime/parachains/src/paras/tests.rs
+++ b/polkadot/runtime/parachains/src/paras/tests.rs
@@ -1457,6 +1457,7 @@ fn pvf_check_submit_vote() {
 
 		let call =
 			Call::include_pvf_check_statement { stmt: stmt.clone(), signature: signature.clone() };
+		#[allow(deprecated)]
 		let validate_unsigned =
 			<Paras as ValidateUnsigned>::validate_unsigned(TransactionSource::InBlock, &call)
 				.map(|_| ());
@@ -2263,6 +2264,7 @@ fn apply_authorized_force_set_current_code_works() {
 	                  code: ValidationCode|
 	 -> (Result<_, _>, DispatchResultWithPostInfo) {
 		let call = Call::apply_authorized_force_set_current_code { para, new_code: code.clone() };
+		#[allow(deprecated)]
 		let validate_unsigned =
 			<Paras as ValidateUnsigned>::validate_unsigned(TransactionSource::InBlock, &call)
 				.map(|_| ());
diff --git a/prdoc/pr_10150.prdoc b/prdoc/pr_10150.prdoc
new file mode 100644
index 0000000000000..5084fdd43f168
--- /dev/null
+++ b/prdoc/pr_10150.prdoc
@@ -0,0 +1,40 @@
+title: Deprecate `ValidateUnsigned` trait and `#[pallet::validate_unsigned]` attribute.
+
+doc:
+  - audience: [Runtime Dev, Runtime User]
+    description: |
+      Deprecate the `ValidateUnsigned` trait and `#[pallet::validate_unsigned]` attribute as part of phase 2 of Extrinsic Horizon.
+
+crates:
+  - name: sp-runtime
+    bump: minor
+  - name: frame-system
+    bump: patch
+  - name: frame-support
+    bump: patch
+  - name: frame-support-procedural
+    bump: patch
+  - name: polkadot-runtime-common
+    bump: patch
+  - name: polkadot-runtime-parachains
+    bump: patch
+  - name: pallet-babe
+    bump: patch
+  - name: pallet-beefy
+    bump: patch
+  - name: pallet-election-provider-multi-phase
+    bump: patch
+  - name: pallet-election-provider-multi-block
+    bump: patch
+  - name: frame-executive
+    bump: patch
+  - name: pallet-grandpa
+    bump: patch
+  - name: pallet-im-online
+    bump: patch
+  - name: pallet-mixnet
+    bump: patch
+  - name: cumulus-pallet-parachain-system
+    bump: patch
+  - name: substrate-test-runtime
+    bump: patch
\ No newline at end of file
diff --git a/substrate/frame/babe/src/lib.rs b/substrate/frame/babe/src/lib.rs
index 3dde0393bc026..aaff956b54fbf 100644
--- a/substrate/frame/babe/src/lib.rs
+++ b/substrate/frame/babe/src/lib.rs
@@ -476,6 +476,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/babe/src/tests.rs b/substrate/frame/babe/src/tests.rs
index 9371a1d0e3ded..1b2fd1490a00b 100644
--- a/substrate/frame/babe/src/tests.rs
+++ b/substrate/frame/babe/src/tests.rs
@@ -717,6 +717,7 @@ fn report_equivocation_invalid_equivocation_proof() {
 }
 
 #[test]
+#[allow(deprecated)]
 fn report_equivocation_validate_unsigned_prevents_duplicates() {
 	use sp_runtime::transaction_validity::{
 		InvalidTransaction, TransactionPriority, TransactionSource, TransactionValidity,
diff --git a/substrate/frame/beefy/src/lib.rs b/substrate/frame/beefy/src/lib.rs
index 992226e5b2164..69b3731a02c11 100644
--- a/substrate/frame/beefy/src/lib.rs
+++ b/substrate/frame/beefy/src/lib.rs
@@ -422,6 +422,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/beefy/src/tests.rs b/substrate/frame/beefy/src/tests.rs
index 0a43831508862..2aa1c5c41bc16 100644
--- a/substrate/frame/beefy/src/tests.rs
+++ b/substrate/frame/beefy/src/tests.rs
@@ -728,6 +728,7 @@ fn report_double_voting_invalid_equivocation_proof() {
 }
 
 #[test]
+#[allow(deprecated)]
 fn report_double_voting_validate_unsigned_prevents_duplicates() {
 	use sp_runtime::transaction_validity::{
 		InvalidTransaction, TransactionPriority, TransactionSource, TransactionValidity,
diff --git a/substrate/frame/election-provider-multi-block/src/lib.rs b/substrate/frame/election-provider-multi-block/src/lib.rs
index 7869c806fcca3..2c15488328fce 100644
--- a/substrate/frame/election-provider-multi-block/src/lib.rs
+++ b/substrate/frame/election-provider-multi-block/src/lib.rs
@@ -2753,9 +2753,7 @@ mod election_provider {
 		Phase,
 	};
 	use frame_election_provider_support::{BoundedSupport, BoundedSupports, ElectionProvider};
-	use frame_support::{
-		assert_storage_noop, testing_prelude::bounded_vec, unsigned::ValidateUnsigned,
-	};
+	use frame_support::{assert_storage_noop, testing_prelude::bounded_vec};
 
 	// This is probably the most important test of all, a basic, correct scenario. This test should
 	// be studied in detail, and all of the branches of how it can go wrong or diverge from the
@@ -3059,7 +3057,9 @@ mod election_provider {
 	}
 
 	#[test]
+	#[allow(deprecated)]
 	fn call_to_elect_should_prevent_any_submission() {
+		use frame_support::unsigned::ValidateUnsigned;
 		ExtBuilder::full().build_and_execute(|| {
 			roll_to_signed_open();
 			assert!(MultiBlock::current_phase().is_signed());
diff --git a/substrate/frame/election-provider-multi-block/src/unsigned/benchmarking.rs b/substrate/frame/election-provider-multi-block/src/unsigned/benchmarking.rs
index 72b3e30ac3ec6..aa249394cfc4f 100644
--- a/substrate/frame/election-provider-multi-block/src/unsigned/benchmarking.rs
+++ b/substrate/frame/election-provider-multi-block/src/unsigned/benchmarking.rs
@@ -45,7 +45,9 @@ mod benchmarks {
 
 		#[block]
 		{
-			assert_ok!(Pallet::<T>::validate_unsigned(TransactionSource::Local, &call));
+			#[allow(deprecated)]
+			let result = Pallet::<T>::validate_unsigned(TransactionSource::Local, &call);
+			assert_ok!(result);
 		}
 
 		Ok(())
diff --git a/substrate/frame/election-provider-multi-block/src/unsigned/mod.rs b/substrate/frame/election-provider-multi-block/src/unsigned/mod.rs
index 8afafd2af5713..e9ea21d8cc1bf 100644
--- a/substrate/frame/election-provider-multi-block/src/unsigned/mod.rs
+++ b/substrate/frame/election-provider-multi-block/src/unsigned/mod.rs
@@ -180,6 +180,7 @@ mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
@@ -370,6 +371,7 @@ mod pallet {
 }
 
 #[cfg(test)]
+#[allow(deprecated)]
 mod validate_unsigned {
 	use frame_election_provider_support::Support;
 	use frame_support::{
diff --git a/substrate/frame/election-provider-multi-phase/src/lib.rs b/substrate/frame/election-provider-multi-phase/src/lib.rs
index 7bdc592476e08..ed970ced1bc3b 100644
--- a/substrate/frame/election-provider-multi-phase/src/lib.rs
+++ b/substrate/frame/election-provider-multi-phase/src/lib.rs
@@ -1214,6 +1214,7 @@ pub mod pallet {
 		PreDispatchDifferentRound,
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/election-provider-multi-phase/src/unsigned.rs b/substrate/frame/election-provider-multi-phase/src/unsigned.rs
index 703e4910b83b8..510e042ac9e6f 100644
--- a/substrate/frame/election-provider-multi-phase/src/unsigned.rs
+++ b/substrate/frame/election-provider-multi-phase/src/unsigned.rs
@@ -1111,13 +1111,17 @@ mod tests {
 	use sp_runtime::{
 		bounded_vec,
 		offchain::storage_lock::{BlockAndTime, StorageLock},
-		traits::{Dispatchable, ValidateUnsigned, Zero},
+		traits::{Dispatchable, Zero},
 		ModuleError, PerU16,
 	};
 
+	#[allow(deprecated)]
+	use sp_runtime::traits::ValidateUnsigned;
+
 	type Assignment = crate::unsigned::Assignment<Runtime>;
 
 	#[test]
+	#[allow(deprecated)]
 	fn validate_unsigned_retracts_wrong_phase() {
 		ExtBuilder::default().desired_targets(0).build_and_execute(|| {
 			let solution = RawSolution::<TestNposSolution> {
@@ -1190,6 +1194,7 @@ mod tests {
 	}
 
 	#[test]
+	#[allow(deprecated)]
 	fn validate_unsigned_retracts_low_score() {
 		ExtBuilder::default().desired_targets(0).build_and_execute(|| {
 			roll_to_unsigned();
@@ -1236,6 +1241,7 @@ mod tests {
 	}
 
 	#[test]
+	#[allow(deprecated)]
 	fn validate_unsigned_retracts_incorrect_winner_count() {
 		ExtBuilder::default().desired_targets(1).build_and_execute(|| {
 			roll_to_unsigned();
@@ -1262,6 +1268,7 @@ mod tests {
 	}
 
 	#[test]
+	#[allow(deprecated)]
 	fn priority_is_set() {
 		ExtBuilder::default()
 			.miner_tx_priority(20)
@@ -1907,6 +1914,7 @@ mod tests {
 	}
 
 	#[test]
+	#[allow(deprecated)]
 	fn ocw_solution_must_have_correct_round() {
 		let (mut ext, pool) = ExtBuilder::default().build_offchainify(0);
 		ext.execute_with(|| {
diff --git a/substrate/frame/executive/src/lib.rs b/substrate/frame/executive/src/lib.rs
index ad1ee38e4ec64..0c7894f98a810 100644
--- a/substrate/frame/executive/src/lib.rs
+++ b/substrate/frame/executive/src/lib.rs
@@ -68,14 +68,6 @@
 //! # use sp_runtime::transaction_validity::{
 //! #    TransactionValidity, UnknownTransaction, TransactionSource,
 //! # };
-//! # use sp_runtime::traits::ValidateUnsigned;
-//! # impl ValidateUnsigned for Runtime {
-//! #     type Call = ();
-//! #
-//! #     fn validate_unsigned(_source: TransactionSource, _call: &Self::Call) -> TransactionValidity {
-//! #         UnknownTransaction::NoUnsignedValidator.into()
-//! #     }
-//! # }
 //! /// Executive: handles dispatch to the various modules.
 //! pub type Executive = executive::Executive<Runtime, Block, Context, Runtime, AllPalletsWithSystem>;
 //! ```
@@ -135,12 +127,15 @@ use sp_runtime::{
 	generic::Digest,
 	traits::{
 		self, Applyable, CheckEqual, Checkable, Dispatchable, Header, LazyBlock, NumberFor, One,
-		ValidateUnsigned, Zero,
+		Zero,
 	},
 	transaction_validity::{TransactionSource, TransactionValidity, TransactionValidityError},
 	ApplyExtrinsicResult, ExtrinsicInclusionMode,
 };
 
+#[allow(deprecated)]
+use sp_runtime::traits::ValidateUnsigned;
+
 #[cfg(feature = "try-runtime")]
 use ::{
 	frame_support::{
diff --git a/substrate/frame/executive/src/tests.rs b/substrate/frame/executive/src/tests.rs
index b12f3aa474824..fa307a2869f31 100644
--- a/substrate/frame/executive/src/tests.rs
+++ b/substrate/frame/executive/src/tests.rs
@@ -145,6 +145,7 @@ mod custom {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
@@ -267,6 +268,7 @@ mod custom2 {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/grandpa/src/lib.rs b/substrate/frame/grandpa/src/lib.rs
index 0451792e977c6..62c191c6f7ab2 100644
--- a/substrate/frame/grandpa/src/lib.rs
+++ b/substrate/frame/grandpa/src/lib.rs
@@ -359,6 +359,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/grandpa/src/tests.rs b/substrate/frame/grandpa/src/tests.rs
index 0960efeb10b2a..2402955c95efe 100644
--- a/substrate/frame/grandpa/src/tests.rs
+++ b/substrate/frame/grandpa/src/tests.rs
@@ -661,6 +661,7 @@ fn report_equivocation_invalid_equivocation_proof() {
 }
 
 #[test]
+#[allow(deprecated)]
 fn report_equivocation_validate_unsigned_prevents_duplicates() {
 	use sp_runtime::transaction_validity::{
 		InvalidTransaction, TransactionPriority, TransactionSource, TransactionValidity,
diff --git a/substrate/frame/im-online/src/benchmarking.rs b/substrate/frame/im-online/src/benchmarking.rs
index 06b7231b1f485..c561e32bcfda6 100644
--- a/substrate/frame/im-online/src/benchmarking.rs
+++ b/substrate/frame/im-online/src/benchmarking.rs
@@ -22,10 +22,7 @@
 use frame_benchmarking::v2::*;
 use frame_support::{traits::UnfilteredDispatchable, WeakBoundedVec};
 use frame_system::RawOrigin;
-use sp_runtime::{
-	traits::{ValidateUnsigned, Zero},
-	transaction_validity::TransactionSource,
-};
+use sp_runtime::{traits::Zero, transaction_validity::TransactionSource};
 
 use crate::*;
 
@@ -83,6 +80,7 @@ mod benchmarks {
 
 		#[block]
 		{
+			#[allow(deprecated)]
 			Pallet::<T>::validate_unsigned(TransactionSource::InBlock, &call)
 				.map_err(<&str>::from)?;
 		}
@@ -100,6 +98,7 @@ mod benchmarks {
 
 		#[block]
 		{
+			#[allow(deprecated)]
 			Pallet::<T>::validate_unsigned(TransactionSource::InBlock, &call)
 				.map_err(<&str>::from)?;
 			<Call<T> as Decode>::decode(&mut &*call_enc)
diff --git a/substrate/frame/im-online/src/lib.rs b/substrate/frame/im-online/src/lib.rs
index dc18f394a767c..0051cdc6c04f7 100644
--- a/substrate/frame/im-online/src/lib.rs
+++ b/substrate/frame/im-online/src/lib.rs
@@ -447,6 +447,7 @@ pub mod pallet {
 	/// incorrect.
 	pub(crate) const INVALID_VALIDATORS_LEN: u8 = 10;
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/im-online/src/tests.rs b/substrate/frame/im-online/src/tests.rs
index 5a5c69b43b122..c8307be138961 100644
--- a/substrate/frame/im-online/src/tests.rs
+++ b/substrate/frame/im-online/src/tests.rs
@@ -120,6 +120,7 @@ fn heartbeat(
 	};
 	let signature = id.sign(&heartbeat.encode()).unwrap();
 
+	#[allow(deprecated)]
 	ImOnline::pre_dispatch(&crate::Call::heartbeat {
 		heartbeat: heartbeat.clone(),
 		signature: signature.clone(),
diff --git a/substrate/frame/mixnet/src/lib.rs b/substrate/frame/mixnet/src/lib.rs
index 8fdadc0dfe6f2..edb43bf6f1c99 100644
--- a/substrate/frame/mixnet/src/lib.rs
+++ b/substrate/frame/mixnet/src/lib.rs
@@ -303,6 +303,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/sassafras/src/lib.rs b/substrate/frame/sassafras/src/lib.rs
index f54387b2a8b6e..1bf8cefa9358a 100644
--- a/substrate/frame/sassafras/src/lib.rs
+++ b/substrate/frame/sassafras/src/lib.rs
@@ -463,6 +463,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
diff --git a/substrate/frame/support/procedural/src/construct_runtime/expand/unsigned.rs b/substrate/frame/support/procedural/src/construct_runtime/expand/unsigned.rs
index 737a39ea681e0..ab30d194d2326 100644
--- a/substrate/frame/support/procedural/src/construct_runtime/expand/unsigned.rs
+++ b/substrate/frame/support/procedural/src/construct_runtime/expand/unsigned.rs
@@ -46,6 +46,7 @@ pub fn expand_outer_validate_unsigned(
 	quote! {
 		#( #query_validate_unsigned_part_macros )*
 
+		#[allow(deprecated)]
 		impl #scrate::unsigned::ValidateUnsigned for #runtime {
 			type Call = RuntimeCall;
 
diff --git a/substrate/frame/support/procedural/src/pallet/expand/validate_unsigned.rs b/substrate/frame/support/procedural/src/pallet/expand/validate_unsigned.rs
index 8769955851712..cd99c7f09c909 100644
--- a/substrate/frame/support/procedural/src/pallet/expand/validate_unsigned.rs
+++ b/substrate/frame/support/procedural/src/pallet/expand/validate_unsigned.rs
@@ -25,6 +25,12 @@ pub fn expand_validate_unsigned(def: &mut Def) -> TokenStream {
 	let macro_ident =
 		Ident::new(&format!("__is_validate_unsigned_part_defined_{}", count), def.item.span());
 
+	let maybe_compile_warning = def
+		.validate_unsigned
+		.as_ref()
+		.and_then(|v| v.warning.as_ref())
+		.map_or_else(|| TokenStream::new(), |w| quote! { #w });
+
 	let maybe_compile_error = if def.validate_unsigned.is_none() {
 		quote! {
 			compile_error!(concat!(
@@ -48,7 +54,7 @@ pub fn expand_validate_unsigned(def: &mut Def) -> TokenStream {
 					#maybe_compile_error
 				}
 			}
-
+			#maybe_compile_warning
 			#[doc(hidden)]
 			pub use #macro_ident as is_validate_unsigned_part_defined;
 		}
diff --git a/substrate/frame/support/procedural/src/pallet/parse/validate_unsigned.rs b/substrate/frame/support/procedural/src/pallet/parse/validate_unsigned.rs
index 9f59d26aac82d..e21735e2e4e7e 100644
--- a/substrate/frame/support/procedural/src/pallet/parse/validate_unsigned.rs
+++ b/substrate/frame/support/procedural/src/pallet/parse/validate_unsigned.rs
@@ -16,10 +16,15 @@
 // limitations under the License.
 
 use super::helper;
+use crate::COUNTER;
+use proc_macro_warning::FormattedWarning;
 use syn::spanned::Spanned;
 
 /// The definition of the pallet validate unsigned implementation.
-pub struct ValidateUnsignedDef {}
+pub struct ValidateUnsignedDef {
+	/// Compile time warning.
+	pub warning: Option<FormattedWarning>,
+}
 
 impl ValidateUnsignedDef {
 	pub fn try_from(item: &mut syn::Item) -> syn::Result<Self> {
@@ -50,6 +55,24 @@ impl ValidateUnsignedDef {
 		helper::check_pallet_struct_usage(&item.self_ty)?;
 		helper::check_impl_gen(&item.generics, item.impl_token.span())?;
 
-		Ok(ValidateUnsignedDef {})
+		// Check if the `#[allow(deprecated)]` attribute is present
+		let allow_dep: syn::Attribute = syn::parse_quote!(#[allow(deprecated)]);
+		let warning = if item.attrs.iter().any(|attr| attr == &allow_dep) {
+			None
+		} else {
+			const DEPRECATION_MSG: &str = "#[pallet::validate_unsigned] will be removed after \
+				April 2027. Use `#[pallet::authorize]` with `frame_system::AuthorizeCall` instead.";
+			const REFERENCE_LINK: &str = "https://github.com/paritytech/polkadot-sdk/issues/2415";
+			let count = COUNTER.with(|counter| counter.borrow_mut().inc());
+			let warning = proc_macro_warning::FormattedWarning::new_deprecated(
+				format!("validate_unsigned_deprecation_{count}"),
+				format!("\n{DEPRECATION_MSG}\n\n\t\tFor more info see:\n\t\t\t{REFERENCE_LINK}"),
+				item.span(),
+			);
+
+			Some(warning)
+		};
+
+		Ok(ValidateUnsignedDef { warning })
 	}
 }
diff --git a/substrate/frame/support/src/lib.rs b/substrate/frame/support/src/lib.rs
index d017a9402a89c..5b4ee6164e5ec 100644
--- a/substrate/frame/support/src/lib.rs
+++ b/substrate/frame/support/src/lib.rs
@@ -96,6 +96,7 @@ pub mod view_functions;
 pub mod weights;
 #[doc(hidden)]
 pub mod unsigned {
+	#[allow(deprecated)]
 	#[doc(hidden)]
 	pub use crate::sp_runtime::traits::ValidateUnsigned;
 	#[doc(hidden)]
@@ -447,8 +448,7 @@ pub mod pallet_prelude {
 	pub use sp_runtime::{
 		traits::{
 			CheckedAdd, CheckedConversion, CheckedDiv, CheckedMul, CheckedShl, CheckedShr,
-			CheckedSub, MaybeSerializeDeserialize, Member, One, ValidateResult, ValidateUnsigned,
-			Zero,
+			CheckedSub, MaybeSerializeDeserialize, Member, One, ValidateResult, Zero,
 		},
 		transaction_validity::{
 			InvalidTransaction, TransactionLongevity, TransactionPriority, TransactionSource,
@@ -458,6 +458,9 @@ pub mod pallet_prelude {
 		Debug, DispatchError, MAX_MODULE_ERROR_ENCODED_SIZE,
 	};
 	pub use sp_weights::Weight;
+
+	#[allow(deprecated)]
+	pub use sp_runtime::traits::ValidateUnsigned;
 }
 
 /// The pallet macro has 2 purposes:
@@ -1213,6 +1216,13 @@ pub mod pallet_macros {
 	/// }
 	pub use frame_support_procedural::composite_enum;
 
+	/// Deprecation Notice
+	///
+	/// The `#[pallet::validate_unsigned]` attribute has been deprecated and will be removed in
+	/// a future release. Use [`sp_runtime::traits::TransactionExtension`] instead.
+	///
+	/// For more information, see: <https://github.com/paritytech/polkadot-sdk/issues/2415>
+	/// ---
 	/// Allows the pallet to validate unsigned transactions.
 	///
 	/// Item must be defined as:
diff --git a/substrate/frame/support/test/tests/pallet.rs b/substrate/frame/support/test/tests/pallet.rs
index 7d50c0008a843..c9e56ae9c9708 100644
--- a/substrate/frame/support/test/tests/pallet.rs
+++ b/substrate/frame/support/test/tests/pallet.rs
@@ -504,6 +504,7 @@ pub mod pallet {
 	)]
 	pub struct Origin<T>(PhantomData<T>);
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T>
 	where
@@ -1074,11 +1075,13 @@ fn inherent_expand() {
 }
 
 #[test]
+#[allow(deprecated)]
 fn validate_unsigned_expand() {
 	use frame_support::pallet_prelude::{
 		InvalidTransaction, TransactionSource, TransactionValidityError, ValidTransaction,
 		ValidateUnsigned,
 	};
+
 	let call = pallet::Call::<Runtime>::foo_no_post_info {};
 
 	let validity = pallet::Pallet::validate_unsigned(TransactionSource::Local, &call).unwrap_err();
diff --git a/substrate/frame/support/test/tests/pallet_instance.rs b/substrate/frame/support/test/tests/pallet_instance.rs
index 0ab763eaa89cd..974f132110f9a 100644
--- a/substrate/frame/support/test/tests/pallet_instance.rs
+++ b/substrate/frame/support/test/tests/pallet_instance.rs
@@ -221,6 +221,7 @@ pub mod pallet {
 	#[scale_info(skip_type_params(T, I))]
 	pub struct Origin<T, I = ()>(PhantomData<(T, I)>);
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config<I>, I: 'static> ValidateUnsigned for Pallet<T, I> {
 		type Call = Call<T, I>;
diff --git a/substrate/frame/support/test/tests/runtime.rs b/substrate/frame/support/test/tests/runtime.rs
index 416fae5feb5fc..b74c9a5bcad41 100644
--- a/substrate/frame/support/test/tests/runtime.rs
+++ b/substrate/frame/support/test/tests/runtime.rs
@@ -33,7 +33,7 @@ use scale_info::TypeInfo;
 use sp_core::sr25519;
 use sp_runtime::{
 	generic,
-	traits::{BlakeTwo256, ValidateUnsigned, Verify},
+	traits::{BlakeTwo256, Verify},
 	DispatchError, ModuleError,
 };
 use sp_version::RuntimeVersion;
@@ -197,6 +197,7 @@ mod nested {
 			fn build(&self) {}
 		}
 
+		#[allow(deprecated)]
 		#[pallet::validate_unsigned]
 		impl<T: Config> ValidateUnsigned for Pallet<T> {
 			type Call = Call<T>;
@@ -285,6 +286,7 @@ pub mod module3 {
 	#[pallet::storage]
 	pub type Storage<T> = StorageValue<_, u32>;
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
@@ -1011,10 +1013,12 @@ fn test_validate_unsigned() {
 	use frame_support::pallet_prelude::*;
 
 	let call = RuntimeCall::NestedModule3(nested::module3::Call::fail {});
+	#[allow(deprecated)]
 	let validity = Runtime::validate_unsigned(TransactionSource::Local, &call).unwrap_err();
 	assert_eq!(validity, TransactionValidityError::Invalid(InvalidTransaction::Call));
 
 	let call = RuntimeCall::Module3(module3::Call::fail {});
+	#[allow(deprecated)]
 	let validity = Runtime::validate_unsigned(TransactionSource::Local, &call).unwrap_err();
 	assert_eq!(
 		validity,
diff --git a/substrate/frame/support/test/tests/runtime_legacy_ordering.rs b/substrate/frame/support/test/tests/runtime_legacy_ordering.rs
index e25c803a56a34..4873c7cb5d1a1 100644
--- a/substrate/frame/support/test/tests/runtime_legacy_ordering.rs
+++ b/substrate/frame/support/test/tests/runtime_legacy_ordering.rs
@@ -33,7 +33,7 @@ use scale_info::TypeInfo;
 use sp_core::sr25519;
 use sp_runtime::{
 	generic,
-	traits::{BlakeTwo256, ValidateUnsigned, Verify},
+	traits::{BlakeTwo256, Verify},
 	DispatchError, ModuleError,
 };
 use sp_version::RuntimeVersion;
@@ -197,6 +197,7 @@ mod nested {
 			fn build(&self) {}
 		}
 
+		#[allow(deprecated)]
 		#[pallet::validate_unsigned]
 		impl<T: Config> ValidateUnsigned for Pallet<T> {
 			type Call = Call<T>;
@@ -285,6 +286,7 @@ pub mod module3 {
 	#[pallet::storage]
 	pub type Storage<T> = StorageValue<_, u32>;
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
@@ -1011,10 +1013,12 @@ fn test_validate_unsigned() {
 	use frame_support::pallet_prelude::*;
 
 	let call = RuntimeCall::NestedModule3(nested::module3::Call::fail {});
+	#[allow(deprecated)]
 	let validity = Runtime::validate_unsigned(TransactionSource::Local, &call).unwrap_err();
 	assert_eq!(validity, TransactionValidityError::Invalid(InvalidTransaction::Call));
 
 	let call = RuntimeCall::Module3(module3::Call::fail {});
+	#[allow(deprecated)]
 	let validity = Runtime::validate_unsigned(TransactionSource::Local, &call).unwrap_err();
 	assert_eq!(
 		validity,
diff --git a/substrate/frame/support/test/tests/tasks.rs b/substrate/frame/support/test/tests/tasks.rs
index 9a61da0ec8f0a..5ec21d609475f 100644
--- a/substrate/frame/support/test/tests/tasks.rs
+++ b/substrate/frame/support/test/tests/tasks.rs
@@ -135,6 +135,7 @@ fn tasks_work() {
 }
 
 #[test]
+#[allow(deprecated)]
 fn do_task_unsigned_validation_rejects_external_source() {
 	new_test_ext().execute_with(|| {
 		use frame_support::pallet_prelude::{
diff --git a/substrate/frame/system/src/lib.rs b/substrate/frame/system/src/lib.rs
index 673ab8d5f6e9d..fb7576141d56c 100644
--- a/substrate/frame/system/src/lib.rs
+++ b/substrate/frame/system/src/lib.rs
@@ -1132,8 +1132,9 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
-	impl<T: Config> sp_runtime::traits::ValidateUnsigned for Pallet<T> {
+	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;
 		fn validate_unsigned(source: TransactionSource, call: &Self::Call) -> TransactionValidity {
 			if let Call::apply_authorized_upgrade { ref code } = call {
diff --git a/substrate/primitives/runtime/src/generic/checked_extrinsic.rs b/substrate/primitives/runtime/src/generic/checked_extrinsic.rs
index 62b738559ed5d..560b7b543c66e 100644
--- a/substrate/primitives/runtime/src/generic/checked_extrinsic.rs
+++ b/substrate/primitives/runtime/src/generic/checked_extrinsic.rs
@@ -23,7 +23,7 @@ use crate::{
 	traits::{
 		self, AsTransactionAuthorizedOrigin, DispatchInfoOf, DispatchTransaction, Dispatchable,
 		ExtensionVariant, InvalidVersion, MaybeDisplay, Member, Pipeline, PostDispatchInfoOf,
-		TransactionExtension, ValidateUnsigned,
+		TransactionExtension,
 	},
 	transaction_validity::{TransactionSource, TransactionValidity},
 };
@@ -90,7 +90,8 @@ where
 {
 	type Call = Call;
 
-	fn validate<I: ValidateUnsigned<Call = Self::Call>>(
+	#[allow(deprecated)]
+	fn validate<I: crate::traits::ValidateUnsigned<Call = Self::Call>>(
 		&self,
 		source: TransactionSource,
 		info: &DispatchInfoOf<Self::Call>,
@@ -114,7 +115,8 @@ where
 		}
 	}
 
-	fn apply<I: ValidateUnsigned<Call = Self::Call>>(
+	#[allow(deprecated)]
+	fn apply<I: crate::traits::ValidateUnsigned<Call = Self::Call>>(
 		self,
 		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
diff --git a/substrate/primitives/runtime/src/traits/mod.rs b/substrate/primitives/runtime/src/traits/mod.rs
index 3dd4173bf19de..28aae6fe2c52c 100644
--- a/substrate/primitives/runtime/src/traits/mod.rs
+++ b/substrate/primitives/runtime/src/traits/mod.rs
@@ -1861,6 +1861,7 @@ pub trait Applyable: Sized + Send + Sync {
 	///
 	/// IMPORTANT: Ensure that *some* origin has been authorized after validating the transaction.
 	/// If no origin was authorized, the transaction must be rejected.
+	#[allow(deprecated)]
 	fn validate<V: ValidateUnsigned<Call = Self::Call>>(
 		&self,
 		source: TransactionSource,
@@ -1873,6 +1874,7 @@ pub trait Applyable: Sized + Send + Sync {
 	///
 	/// IMPORTANT: Ensure that *some* origin has been authorized after validating the
 	/// transaction. If no origin was authorized, the transaction must be rejected.
+	#[allow(deprecated)]
 	fn apply<V: ValidateUnsigned<Call = Self::Call>>(
 		self,
 		info: &DispatchInfoOf<Self::Call>,
@@ -1899,6 +1901,16 @@ pub trait GetNodeBlockType {
 /// function is called right before dispatching the call wrapped by an unsigned extrinsic. The
 /// [`validate_unsigned`](Self::validate_unsigned) function is mainly being used in the context of
 /// the transaction pool to check the validity of the call wrapped by an unsigned extrinsic.
+///
+/// # Deprecation Notice
+///
+/// This trait is deprecated and will be removed after April 2027. Use
+/// `#[pallet::authorize]` with `frame_system::AuthorizeCall` transaction extension instead.
+///
+/// For more information, see: <https://github.com/paritytech/polkadot-sdk/issues/2415>
+#[deprecated(
+	note = "`ValidateUnsigned` will be removed after April 2027. Use `#[pallet::authorize]` with `frame_system::AuthorizeCall` instead. See https://github.com/paritytech/polkadot-sdk/issues/2415"
+)]
 pub trait ValidateUnsigned {
 	/// The call to validate
 	type Call;
diff --git a/substrate/test-utils/runtime/src/lib.rs b/substrate/test-utils/runtime/src/lib.rs
index ff59929d4e59c..637aabddcf93e 100644
--- a/substrate/test-utils/runtime/src/lib.rs
+++ b/substrate/test-utils/runtime/src/lib.rs
@@ -1266,6 +1266,7 @@ mod tests {
 	}
 
 	#[test]
+	#[allow(deprecated)]
 	fn validate_unsigned_works() {
 		sp_tracing::try_init_simple();
 		new_test_ext().execute_with(|| {
diff --git a/substrate/test-utils/runtime/src/substrate_test_pallet.rs b/substrate/test-utils/runtime/src/substrate_test_pallet.rs
index b128935aff509..7cf931f0e744d 100644
--- a/substrate/test-utils/runtime/src/substrate_test_pallet.rs
+++ b/substrate/test-utils/runtime/src/substrate_test_pallet.rs
@@ -217,6 +217,7 @@ pub mod pallet {
 		}
 	}
 
+	#[allow(deprecated)]
 	#[pallet::validate_unsigned]
 	impl<T: Config> ValidateUnsigned for Pallet<T> {
 		type Call = Call<T>;