diff --git a/crates/cheatcodes/assets/cheatcodes.json b/crates/cheatcodes/assets/cheatcodes.json
index dea51432227f..69cea1943593 100644
--- a/crates/cheatcodes/assets/cheatcodes.json
+++ b/crates/cheatcodes/assets/cheatcodes.json
@@ -4798,6 +4798,26 @@
       "status": "stable",
       "safety": "safe"
     },
+    {
+      "func": {
+        "id": "indexOf",
+        "description": "Returns the index of the first occurrence of a `key` in an `input` string.\nReturns `NOT_FOUND` (i.e. `type(uint256).max`) if the `key` is not found.\nReturns 0 in case of an empty `key`.",
+        "declaration": "function indexOf(string memory input, string memory key) external pure returns (uint256);",
+        "visibility": "external",
+        "mutability": "pure",
+        "signature": "indexOf(string,string)",
+        "selector": "0x8a0807b7",
+        "selectorBytes": [
+          138,
+          8,
+          7,
+          183
+        ]
+      },
+      "group": "string",
+      "status": "stable",
+      "safety": "safe"
+    },
     {
       "func": {
         "id": "isDir",
diff --git a/crates/cheatcodes/spec/src/vm.rs b/crates/cheatcodes/spec/src/vm.rs
index 8f0de363a7fa..cb4ec7304ae1 100644
--- a/crates/cheatcodes/spec/src/vm.rs
+++ b/crates/cheatcodes/spec/src/vm.rs
@@ -1678,6 +1678,11 @@ interface Vm {
     /// Splits the given `string` into an array of strings divided by the `delimiter`.
     #[cheatcode(group = String)]
     function split(string calldata input, string calldata delimiter) external pure returns (string[] memory outputs);
+    /// Returns the index of the first occurrence of a `key` in an `input` string.
+    /// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `key` is not found.
+    /// Returns 0 in case of an empty `key`.
+    #[cheatcode(group = String)]
+    function indexOf(string memory input, string memory key) external pure returns (uint256);
 
     // ======== JSON Parsing and Manipulation ========
 
diff --git a/crates/cheatcodes/src/string.rs b/crates/cheatcodes/src/string.rs
index b7992b9450fd..c98560a72f06 100644
--- a/crates/cheatcodes/src/string.rs
+++ b/crates/cheatcodes/src/string.rs
@@ -2,6 +2,7 @@
 
 use crate::{Cheatcode, Cheatcodes, Result, Vm::*};
 use alloy_dyn_abi::{DynSolType, DynSolValue};
+use alloy_primitives::U256;
 use alloy_sol_types::SolValue;
 
 // address
@@ -135,6 +136,14 @@ impl Cheatcode for splitCall {
     }
 }
 
+// indexOf
+impl Cheatcode for indexOfCall {
+    fn apply(&self, _state: &mut Cheatcodes) -> Result {
+        let Self { input, key } = self;
+        Ok(input.find(key).map(U256::from).unwrap_or(U256::MAX).abi_encode())
+    }
+}
+
 pub(super) fn parse(s: &str, ty: &DynSolType) -> Result {
     parse_value(s, ty).map(|v| v.abi_encode())
 }
diff --git a/testdata/cheats/Vm.sol b/testdata/cheats/Vm.sol
index 2116acf2b8ff..aff05c278740 100644
--- a/testdata/cheats/Vm.sol
+++ b/testdata/cheats/Vm.sol
@@ -237,6 +237,7 @@ interface Vm {
     function getNonce(address account) external view returns (uint64 nonce);
     function getNonce(Wallet calldata wallet) external returns (uint64 nonce);
     function getRecordedLogs() external returns (Log[] memory logs);
+    function indexOf(string memory input, string memory key) external pure returns (uint256);
     function isDir(string calldata path) external returns (bool result);
     function isFile(string calldata path) external returns (bool result);
     function isPersistent(address account) external view returns (bool persistent);
diff --git a/testdata/default/cheats/StringUtils.t.sol b/testdata/default/cheats/StringUtils.t.sol
index 471d628be018..136164a413d7 100644
--- a/testdata/default/cheats/StringUtils.t.sol
+++ b/testdata/default/cheats/StringUtils.t.sol
@@ -39,4 +39,16 @@ contract StringManipulationTest is DSTest {
         assertEq("World", splitResult[1]);
         assertEq("Reth", splitResult[2]);
     }
+
+    function testIndexOf() public {
+        string memory input = "Hello, World!";
+        string memory key1 = "Hello,";
+        string memory key2 = "World!";
+        string memory key3 = "";
+        string memory key4 = "foundry";
+        assertEq(vm.indexOf(input, key1), 0);
+        assertEq(vm.indexOf(input, key2), 7);
+        assertEq(vm.indexOf(input, key3), 0);
+        assertEq(vm.indexOf(input, key4), type(uint256).max);
+    }
 }