diff --git a/src/WeirollWallet.sol b/src/WeirollWallet.sol
index f3f6c24..c7d69d5 100644
--- a/src/WeirollWallet.sol
+++ b/src/WeirollWallet.sol
@@ -3,12 +3,20 @@ pragma solidity ^0.8.0;
 
 import { VM } from "lib/weiroll/contracts/VM.sol";
 import { Clone } from "lib/clones-with-immutable-args/src/Clone.sol";
+import { IERC1271 } from "src/interfaces/IERC1271.sol";
+import { ECDSA } from "lib/solady/src/utils/ECDSA.sol";
 
 /// @title WeirollWallet
 /// @author Royco
 /// @notice WeirollWallet implementation contract.
 /// @notice Implements a simple smart contract wallet that can execute Weiroll VM commands
-contract WeirollWallet is Clone, VM {
+contract WeirollWallet is IERC1271, Clone, VM {
+    // Returned to indicate a valid ERC1271 signature
+    bytes4 internal constant ERC1271_MAGIC_VALUE = 0x1626ba7e; // bytes4(keccak256("isValidSignature(bytes32,bytes)")
+
+    // Returned to indicate an invalid ERC1271 signature
+    bytes4 internal constant INVALID_SIGNATURE = 0x00000000;
+
     /// @notice Let the Weiroll Wallet receive ether directly if needed
     receive() external payable { }
     /// @notice Also allow a fallback with no logic if erroneous data is provided
@@ -139,4 +147,17 @@ contract WeirollWallet is Clone, VM {
         emit WeirollWalletExecutedManually();
         return result;
     }
+
+    /// @notice Check if signature is valid for this contract
+    /// @dev Signature is valid if the signer is the owner of this wallet
+    /// @param digest Hash of the message to validate the signature against
+    /// @param signature Signature produced for the provided digest
+    function isValidSignature(bytes32 digest, bytes calldata signature) external view returns (bytes4) {
+        // Modify digest to include the chainId and address of this wallet to prevent replay attacks
+        bytes32 walletSpecificDigest = keccak256(abi.encode(digest, block.chainid, address(this)));
+        // Check if signature was produced by owner of this wallet
+        // Don't revert on failure. Simply return INVALID_SIGNATURE.
+        if (ECDSA.tryRecover(walletSpecificDigest, signature) == owner()) return ERC1271_MAGIC_VALUE;
+        else return INVALID_SIGNATURE;
+    }
 }
diff --git a/src/interfaces/IERC1271.sol b/src/interfaces/IERC1271.sol
new file mode 100644
index 0000000..1150c04
--- /dev/null
+++ b/src/interfaces/IERC1271.sol
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.0;
+
+/// @title IERC1271
+/// @notice Interface defined by EIP-1271
+/// @dev Interface for verifying contract account signatures
+interface IERC1271 {
+    /// @notice Returns whether the provided signature is valid for the provided data
+    /// @dev Returns 0x1626ba7e (magic value) when function passes.
+    /// @param digest Hash of the message to validate the signature against
+    /// @param signature Signature produced for the provided digest
+    function isValidSignature(bytes32 digest, bytes memory signature) external view returns (bytes4);
+}
diff --git a/test/WeirollWallet.t.sol b/test/WeirollWallet.t.sol
index 29267ec..322896a 100644
--- a/test/WeirollWallet.t.sol
+++ b/test/WeirollWallet.t.sol
@@ -5,6 +5,7 @@ import { WeirollWallet } from "src/WeirollWallet.sol";
 import { ClonesWithImmutableArgs } from "lib/clones-with-immutable-args/src/ClonesWithImmutableArgs.sol";
 import { Test } from "forge-std/Test.sol";
 import { VM } from "lib/weiroll/contracts/VM.sol";
+import { ECDSA } from "lib/solady/src/utils/ECDSA.sol";
 
 contract WeirollWalletTest is Test {
     using ClonesWithImmutableArgs for address;
@@ -39,8 +40,9 @@ contract WeirollWalletTest is Test {
         public
         returns (WeirollWallet)
     {
-        return
-            WeirollWallet(payable(WEIROLL_WALLET_IMPLEMENTATION.clone(abi.encodePacked(_owner, _recipeMarketHub, _amount, _lockedUntil, _isForfeitable, _marketHash))));
+        return WeirollWallet(
+            payable(WEIROLL_WALLET_IMPLEMENTATION.clone(abi.encodePacked(_owner, _recipeMarketHub, _amount, _lockedUntil, _isForfeitable, _marketHash)))
+        );
     }
 
     function testWalletInitialization() public view {
@@ -152,6 +154,43 @@ contract WeirollWalletTest is Test {
         // Check if the balance increased
         assertEq(address(wallet).balance, initialBalance + 1 ether);
     }
+
+    function testIsValidSignatureFuzz(uint256 ownerPrivateKey, bytes32 digest, bytes memory signature) public {
+        // Avoid using zero private key and have it be in the correct range for secp256k1 SKs
+        vm.assume(
+            ownerPrivateKey != 0 && ownerPrivateKey < 115_792_089_237_316_195_423_570_985_008_687_907_852_837_564_279_074_904_382_605_163_141_518_161_494_337
+        );
+        // Initialize owner address from the private key
+        owner = vm.addr(ownerPrivateKey);
+
+        // Create a new wallet with the fuzzed owner
+        wallet = createWallet(owner, address(mockRecipeMarketHub), AMOUNT, lockedUntil, true, marketHash);
+
+        // Modify digest for replay protection
+        bytes32 walletSpecificDigest = keccak256(abi.encode(digest, block.chainid, address(wallet)));
+
+        // Create a valid signature from the owner
+        (uint8 v, bytes32 r, bytes32 s) = vm.sign(ownerPrivateKey, walletSpecificDigest);
+        bytes memory validSignature = abi.encodePacked(r, s, v);
+
+        // Test valid signature
+        bytes4 validResult = wallet.isValidSignature(digest, validSignature);
+        bytes4 expectedMagicValue = 0x1626ba7e; // ERC1271_MAGIC_VALUE
+        assertEq(validResult, expectedMagicValue);
+
+        // Skip invalid signature lengths
+        if (signature.length != 64 && signature.length != 65) {
+            return;
+        }
+
+        // Test invalid signature
+        bytes4 invalidResult = wallet.isValidSignature(digest, signature);
+        assertEq(invalidResult, 0x00000000); // INVALID_SIGNATURE
+
+        // Ensure the owner address is correctly recovered
+        address recoveredSigner = ECDSA.recover(walletSpecificDigest, validSignature);
+        assertEq(recoveredSigner, owner);
+    }
 }
 
 contract MockRecipeMarketHub {