diff --git a/foundation/src/main/resources/chains.yaml b/foundation/src/main/resources/chains.yaml
index 0ce32f25..19d4b98d 100644
--- a/foundation/src/main/resources/chains.yaml
+++ b/foundation/src/main/resources/chains.yaml
@@ -438,6 +438,12 @@ chain-settings:
           grpcId: 10023
           short-names: [mantle-testnet]
           chain-id: 0x1389
+        - id: Sepolia
+          priority: 10
+          code: MANTLE_SEPOLIA
+          grpcId: 10066
+          short-names: [mantle-sepolia]
+          chain-id: 0x138b
     - id: klaytn
       label: Klaytn
       type: eth
@@ -1268,4 +1274,4 @@ chain-settings:
           code: TELOS_TESTNET
           grpcId: 10063
           short-names: [ telos-testnet ]
-          chain-id: 0x29
\ No newline at end of file
+          chain-id: 0x29