diff --git a/packages/name-controller/src/constants.ts b/packages/name-controller/src/constants.ts
index 6a5b4767f5..0c1e930c43 100644
--- a/packages/name-controller/src/constants.ts
+++ b/packages/name-controller/src/constants.ts
@@ -6,7 +6,7 @@ export const CHAIN_IDS = {
   BSC: '0x38',
   BSC_TESTNET: '0x61',
   OPTIMISM: '0xa',
-  OPTIMISM_TESTNET: '0x1a4',
+  OPTIMISM_SEPOLIA: '0xaa37dc',
   POLYGON: '0x89',
   POLYGON_TESTNET: '0x13881',
   AVALANCHE: '0xa86a',
@@ -58,9 +58,9 @@ export const ETHERSCAN_SUPPORTED_NETWORKS = {
     domain: DEFAULT_ETHERSCAN_DOMAIN,
     subdomain: `${DEFAULT_ETHERSCAN_SUBDOMAIN_PREFIX}-optimistic`,
   },
-  [CHAIN_IDS.OPTIMISM_TESTNET]: {
+  [CHAIN_IDS.OPTIMISM_SEPOLIA]: {
     domain: DEFAULT_ETHERSCAN_DOMAIN,
-    subdomain: `${DEFAULT_ETHERSCAN_SUBDOMAIN_PREFIX}-goerli-optimistic`,
+    subdomain: `${DEFAULT_ETHERSCAN_SUBDOMAIN_PREFIX}-sepolia-optimistic`,
   },
   [CHAIN_IDS.POLYGON]: {
     domain: 'polygonscan.com',
diff --git a/packages/preferences-controller/src/PreferencesController.ts b/packages/preferences-controller/src/PreferencesController.ts
index b7e53e5d69..540d841c8c 100644
--- a/packages/preferences-controller/src/PreferencesController.ts
+++ b/packages/preferences-controller/src/PreferencesController.ts
@@ -178,7 +178,7 @@ export function getDefaultPreferencesState() {
       [ETHERSCAN_SUPPORTED_CHAIN_IDS.BSC]: true,
       [ETHERSCAN_SUPPORTED_CHAIN_IDS.BSC_TESTNET]: true,
       [ETHERSCAN_SUPPORTED_CHAIN_IDS.OPTIMISM]: true,
-      [ETHERSCAN_SUPPORTED_CHAIN_IDS.OPTIMISM_TESTNET]: true,
+      [ETHERSCAN_SUPPORTED_CHAIN_IDS.OPTIMISM_SEPOLIA]: true,
       [ETHERSCAN_SUPPORTED_CHAIN_IDS.POLYGON]: true,
       [ETHERSCAN_SUPPORTED_CHAIN_IDS.POLYGON_TESTNET]: true,
       [ETHERSCAN_SUPPORTED_CHAIN_IDS.AVALANCHE]: true,
diff --git a/packages/preferences-controller/src/constants.ts b/packages/preferences-controller/src/constants.ts
index 2fd321a5a9..e546c999ec 100644
--- a/packages/preferences-controller/src/constants.ts
+++ b/packages/preferences-controller/src/constants.ts
@@ -4,7 +4,7 @@ export const ETHERSCAN_SUPPORTED_CHAIN_IDS = {
   BSC: '0x38',
   BSC_TESTNET: '0x61',
   OPTIMISM: '0xa',
-  OPTIMISM_TESTNET: '0x1a4',
+  OPTIMISM_SEPOLIA: '0xaa37dc',
   POLYGON: '0x89',
   POLYGON_TESTNET: '0x13881',
   AVALANCHE: '0xa86a',
diff --git a/packages/transaction-controller/src/constants.ts b/packages/transaction-controller/src/constants.ts
index d35ff04335..2b73c35f01 100644
--- a/packages/transaction-controller/src/constants.ts
+++ b/packages/transaction-controller/src/constants.ts
@@ -4,7 +4,7 @@ export const CHAIN_IDS = {
   BSC: '0x38',
   BSC_TESTNET: '0x61',
   OPTIMISM: '0xa',
-  OPTIMISM_TESTNET: '0x1a4',
+  OPTIMISM_SEPOLIA: '0xaa37dc',
   POLYGON: '0x89',
   POLYGON_TESTNET: '0x13881',
   AVALANCHE: '0xa86a',
@@ -58,9 +58,9 @@ export const ETHERSCAN_SUPPORTED_NETWORKS = {
     domain: DEFAULT_ETHERSCAN_DOMAIN,
     subdomain: `${DEFAULT_ETHERSCAN_SUBDOMAIN_PREFIX}-optimistic`,
   },
-  [CHAIN_IDS.OPTIMISM_TESTNET]: {
+  [CHAIN_IDS.OPTIMISM_SEPOLIA]: {
     domain: DEFAULT_ETHERSCAN_DOMAIN,
-    subdomain: `${DEFAULT_ETHERSCAN_SUBDOMAIN_PREFIX}-goerli-optimistic`,
+    subdomain: `${DEFAULT_ETHERSCAN_SUBDOMAIN_PREFIX}-sepolia-optimistic`,
   },
   [CHAIN_IDS.POLYGON]: {
     domain: 'polygonscan.com',
@@ -106,5 +106,5 @@ export const ETHERSCAN_SUPPORTED_NETWORKS = {
 
 export const GAS_BUFFER_CHAIN_OVERRIDES = {
   [CHAIN_IDS.OPTIMISM]: 1,
-  [CHAIN_IDS.OPTIMISM_TESTNET]: 1,
+  [CHAIN_IDS.OPTIMISM_SEPOLIA]: 1,
 };