diff --git a/.changeset/purple-elephants-wash.md b/.changeset/purple-elephants-wash.md
new file mode 100644
index 0000000000..f77958df1f
--- /dev/null
+++ b/.changeset/purple-elephants-wash.md
@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Added heco chain.
diff --git a/src/chains/definitions/heco.ts b/src/chains/definitions/heco.ts
new file mode 100644
index 0000000000..ee0f9db5bd
--- /dev/null
+++ b/src/chains/definitions/heco.ts
@@ -0,0 +1,20 @@
+import { defineChain } from '../../utils/chain/defineChain.js'
+
+export const heco = /*#__PURE__*/ defineChain({
+  id: 128,
+  name: 'Huobi ECO Chain Mainnet',
+  nativeCurrency: { name: 'HT', symbol: 'HT', decimals: 18 },
+  rpcUrls: {
+    default: {
+      http: ['https://http-mainnet.hecochain.com'],
+      webSocket: ['wss://ws-mainnet.hecochain.com'],
+    },
+  },
+  blockExplorers: {
+    default: {
+      name: 'Heco Scan',
+      url: 'https://hecoscan.io',
+    },
+  },
+  testnet: false,
+})
diff --git a/src/chains/index.ts b/src/chains/index.ts
index da5a6fb36e..1fbfe68909 100644
--- a/src/chains/index.ts
+++ b/src/chains/index.ts
@@ -176,6 +176,7 @@ export { haqqTestedge2 } from './definitions/haqqTestedge2.js'
 export { hardhat } from './definitions/hardhat.js'
 export { harmonyOne } from './definitions/harmonyOne.js'
 export { hashkeyTestnet } from './definitions/hashkeyChainTestnet.js'
+export { heco } from './definitions/heco.js'
 export { hedera } from './definitions/hedera.js'
 export { hederaPreviewnet } from './definitions/hederaPreviewnet.js'
 export { hederaTestnet } from './definitions/hederaTestnet.js'