diff --git a/src/SwapsController.test.ts b/src/SwapsController.test.ts
index 7fa6b916..0de981c4 100644
--- a/src/SwapsController.test.ts
+++ b/src/SwapsController.test.ts
@@ -54,6 +54,7 @@ const {
   LINEA_CHAIN_ID,
   OPTIMISM_CHAIN_ID,
   POLYGON_CHAIN_ID,
+  SEI_CHAIN_ID,
   SWAPS_CONTRACT_ADDRESSES,
   SWAPS_TESTNET_CHAIN_ID,
   ZKSYNC_ERA_CHAIN_ID,
@@ -71,6 +72,7 @@ const INITIAL_CONTROLLER_OPTIONS = {
     swapsUtil.SWAPS_TESTNET_CHAIN_ID,
     swapsUtil.POLYGON_CHAIN_ID,
     swapsUtil.AVALANCHE_CHAIN_ID,
+    swapsUtil.SEI_CHAIN_ID,
   ],
   clientId: undefined,
 };
@@ -3615,6 +3617,7 @@ describe('SwapsController', () => {
         LINEA_CHAIN_ID,
         SWAPS_TESTNET_CHAIN_ID,
         BASE_CHAIN_ID,
+        SEI_CHAIN_ID,
       ]) {
         const chainName = CHAIN_ID_TO_NAME_MAP[chainId];
         describe(`given the ID of a network client for ${chainName}`, () => {
diff --git a/src/SwapsController.ts b/src/SwapsController.ts
index 366d5977..02262653 100644
--- a/src/SwapsController.ts
+++ b/src/SwapsController.ts
@@ -52,6 +52,7 @@ import {
   NATIVE_SWAPS_TOKEN_ADDRESS,
   OPTIMISM_CHAIN_ID,
   POLYGON_CHAIN_ID,
+  SEI_CHAIN_ID,
   shouldEnableDirectWrapping,
   SWAPS_TESTNET_CHAIN_ID,
   SwapsError,
@@ -541,6 +542,7 @@ export default class SwapsController extends BaseController<
         SWAPS_TESTNET_CHAIN_ID,
         POLYGON_CHAIN_ID,
         AVALANCHE_CHAIN_ID,
+        SEI_CHAIN_ID,
       ],
       clientId,
       messenger,
diff --git a/src/constants.ts b/src/constants.ts
index 669f22a3..f3154c57 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -23,6 +23,7 @@ export const ZKSYNC_ERA_CHAIN_ID = toHex('324');
 export const LINEA_CHAIN_ID = toHex('59144');
 export const SWAPS_TESTNET_CHAIN_ID = toHex('1337');
 export const BASE_CHAIN_ID = toHex('8453');
+export const SEI_CHAIN_ID = toHex('1329');
 
 export const CHAIN_ID_TO_NAME_MAP: { [key: string]: string } = {
   [ETH_CHAIN_ID]: 'ethereum',
@@ -35,6 +36,7 @@ export const CHAIN_ID_TO_NAME_MAP: { [key: string]: string } = {
   [LINEA_CHAIN_ID]: 'linea',
   [SWAPS_TESTNET_CHAIN_ID]: 'ethereum',
   [BASE_CHAIN_ID]: 'base',
+  [SEI_CHAIN_ID]: 'sei',
 };
 
 //* APIs base urls
@@ -63,6 +65,8 @@ export const LINEA_SWAPS_CONTRACT_ADDRESS =
   '0x9dda6ef3d919c9bc8885d5560999a3640431e8e6';
 export const BASE_SWAPS_CONTRACT_ADDRESS =
   '0x9dda6ef3d919c9bc8885d5560999a3640431e8e6';
+export const SEI_SWAPS_CONTRACT_ADDRESS =
+  '0x962287c9d5B8a682389E61edAE90ec882325d08b';
 
 export const WETH_CONTRACT_ADDRESS =
   '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2';
@@ -82,6 +86,8 @@ export const WETH_LINEA_CONTRACT_ADDRESS =
   '0xe5D7C2a44FfDDf6b295A15c148167daaAf5Cf34f';
 export const WETH_BASE_CONTRACT_ADDRESS =
   '0x4200000000000000000000000000000000000006';
+export const WSEI_SEI_CONTRACT_ADDRESS =
+  '0xe30fedd158a2e3b13e9badaeabafc5516e95e8c7';
 
 export const SWAPS_WRAPPED_TOKENS_ADDRESSES: { [key: string]: string } = {
   [ETH_CHAIN_ID]: WETH_CONTRACT_ADDRESS,
@@ -94,6 +100,7 @@ export const SWAPS_WRAPPED_TOKENS_ADDRESSES: { [key: string]: string } = {
   [ZKSYNC_ERA_CHAIN_ID]: WETH_ZKSYNC_ERA_CONTRACT_ADDRESS,
   [LINEA_CHAIN_ID]: WETH_LINEA_CONTRACT_ADDRESS,
   [BASE_CHAIN_ID]: WETH_BASE_CONTRACT_ADDRESS,
+  [SEI_CHAIN_ID]: WSEI_SEI_CONTRACT_ADDRESS,
 };
 
 export const SWAPS_CONTRACT_ADDRESSES: { [key: string]: string } = {
@@ -107,6 +114,7 @@ export const SWAPS_CONTRACT_ADDRESSES: { [key: string]: string } = {
   [ZKSYNC_ERA_CHAIN_ID]: ZKSYNC_ERA_SWAPS_CONTRACT_ADDRESS,
   [LINEA_CHAIN_ID]: LINEA_SWAPS_CONTRACT_ADDRESS,
   [BASE_CHAIN_ID]: BASE_SWAPS_CONTRACT_ADDRESS,
+  [SEI_CHAIN_ID]: SEI_SWAPS_CONTRACT_ADDRESS,
 };
 
 export const ALLOWED_CONTRACT_ADDRESSES: { [key: string]: string[] } = {
@@ -150,6 +158,10 @@ export const ALLOWED_CONTRACT_ADDRESSES: { [key: string]: string[] } = {
     SWAPS_CONTRACT_ADDRESSES[BASE_CHAIN_ID],
     SWAPS_WRAPPED_TOKENS_ADDRESSES[BASE_CHAIN_ID],
   ],
+  [SEI_CHAIN_ID]: [
+    SWAPS_CONTRACT_ADDRESSES[SEI_CHAIN_ID],
+    SWAPS_WRAPPED_TOKENS_ADDRESSES[SEI_CHAIN_ID],
+  ],
 };
 
 //* Tokens
@@ -185,6 +197,13 @@ export const AVALANCHE_SWAPS_TOKEN_OBJECT: SwapsToken = {
   decimals: 18,
 };
 
+export const SEI_SWAPS_TOKEN_OBJECT: SwapsToken = {
+  symbol: 'SEI',
+  name: 'Sei',
+  address: NATIVE_SWAPS_TOKEN_ADDRESS,
+  decimals: 18,
+};
+
 export const ARBITRUM_SWAPS_TOKEN_OBJECT: SwapsToken = {
   ...ETH_SWAPS_TOKEN_OBJECT,
 };
@@ -216,6 +235,7 @@ export const SWAPS_NATIVE_TOKEN_OBJECTS: { [key: string]: SwapsToken } = {
   [ZKSYNC_ERA_CHAIN_ID]: ZKSYNC_ERA_SWAPS_TOKEN_OBJECT,
   [LINEA_CHAIN_ID]: LINEA_SWAPS_TOKEN_OBJECT,
   [BASE_CHAIN_ID]: BASE_SWAPS_TOKEN_OBJECT,
+  [SEI_CHAIN_ID]: SEI_SWAPS_TOKEN_OBJECT,
 };
 
 //* Other