diff --git a/packages/dev/src/main.ts b/packages/dev/src/main.ts
index f85a8504..3325edd8 100644
--- a/packages/dev/src/main.ts
+++ b/packages/dev/src/main.ts
@@ -555,7 +555,6 @@ export class NetlifyDev {
         projectRoot: this.#projectRoot,
         settings: {},
         siteId: this.#siteID,
-        timeouts: {},
         userFunctionsPath: userFunctionsPathExists ? userFunctionsPath : undefined,
       })
     }
diff --git a/packages/functions/dev/src/registry.test.ts b/packages/functions/dev/src/registry.test.ts
new file mode 100644
index 00000000..21271dbe
--- /dev/null
+++ b/packages/functions/dev/src/registry.test.ts
@@ -0,0 +1,152 @@
+import { describe, expect, test } from 'vitest'
+
+import { SYNCHRONOUS_FUNCTION_TIMEOUT, BACKGROUND_FUNCTION_TIMEOUT } from '@netlify/functions'
+import { FunctionsRegistry } from './registry.js'
+
+describe('FunctionsRegistry timeout configuration', () => {
+  test('uses default timeouts when no config or override provided', () => {
+    const registry = new FunctionsRegistry({
+      config: {},
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: SYNCHRONOUS_FUNCTION_TIMEOUT,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+
+  test('uses functions_timeout from siteInfo for sync functions only', () => {
+    const registry = new FunctionsRegistry({
+      config: {
+        siteInfo: {
+          functions_timeout: 60,
+        },
+      },
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: 60,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+
+  test('uses functions_config.timeout from siteInfo for sync functions only', () => {
+    const registry = new FunctionsRegistry({
+      config: {
+        siteInfo: {
+          functions_config: {
+            timeout: 45,
+          },
+        },
+      },
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: 45,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+
+  test('prefers functions_timeout over functions_config.timeout for sync functions', () => {
+    const registry = new FunctionsRegistry({
+      config: {
+        siteInfo: {
+          functions_timeout: 60,
+          functions_config: {
+            timeout: 45,
+          },
+        },
+      },
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: 60,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+
+  test('uses override timeouts when provided', () => {
+    const registry = new FunctionsRegistry({
+      config: {
+        siteInfo: {
+          functions_timeout: 60,
+        },
+      },
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+      timeouts: {
+        syncFunctions: 120,
+        backgroundFunctions: 1800,
+      },
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: 120,
+      backgroundFunctions: 1800,
+    })
+  })
+
+  test('allows partial override of timeouts', () => {
+    const registry = new FunctionsRegistry({
+      config: {
+        siteInfo: {
+          functions_timeout: 60,
+        },
+      },
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+      timeouts: {
+        syncFunctions: 120,
+      },
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: 120,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+
+  test('falls back to defaults when siteInfo is undefined', () => {
+    const registry = new FunctionsRegistry({
+      config: {
+        siteInfo: undefined,
+      },
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: SYNCHRONOUS_FUNCTION_TIMEOUT,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+
+  test('falls back to defaults when config is empty object', () => {
+    const registry = new FunctionsRegistry({
+      config: {},
+      destPath: '/tmp/test',
+      projectRoot: '/tmp/project',
+      settings: {},
+    })
+
+    expect(registry.timeouts).toEqual({
+      syncFunctions: SYNCHRONOUS_FUNCTION_TIMEOUT,
+      backgroundFunctions: BACKGROUND_FUNCTION_TIMEOUT,
+    })
+  })
+})
diff --git a/packages/functions/dev/src/registry.ts b/packages/functions/dev/src/registry.ts
index 8f0d3234..c6b4cdf2 100644
--- a/packages/functions/dev/src/registry.ts
+++ b/packages/functions/dev/src/registry.ts
@@ -5,6 +5,7 @@ import { env } from 'node:process'
 
 import type { EnvironmentContext as BlobsContext } from '@netlify/blobs'
 import { DevEventHandler, watchDebounced } from '@netlify/dev-utils'
+import { SYNCHRONOUS_FUNCTION_TIMEOUT, BACKGROUND_FUNCTION_TIMEOUT } from '@netlify/functions'
 import { ListedFunction, listFunctions, Manifest } from '@netlify/zip-it-and-ship-it'
 import extractZip from 'extract-zip'
 
@@ -37,7 +38,7 @@ export interface FunctionRegistryOptions {
   manifest?: Manifest
   projectRoot: string
   settings: any
-  timeouts: any
+  timeouts?: { syncFunctions?: number; backgroundFunctions?: number }
   watch?: boolean
 }
 
@@ -100,7 +101,16 @@ export class FunctionsRegistry {
     this.handleEvent = eventHandler ?? (() => {})
     this.internalFunctionsPath = internalFunctionsPath
     this.projectRoot = projectRoot
-    this.timeouts = timeouts
+
+    // Calculate timeouts from config if not provided as override
+    const siteTimeout = config?.siteInfo?.functions_timeout ?? config?.siteInfo?.functions_config?.timeout
+    this.timeouts = {
+      syncFunctions: timeouts?.syncFunctions ?? siteTimeout ?? SYNCHRONOUS_FUNCTION_TIMEOUT,
+      // NOTE: This isn't documented, but the generically named "functions timeout" config fields only
+      // apply to synchronous Netlify Functions.
+      backgroundFunctions: timeouts?.backgroundFunctions ?? BACKGROUND_FUNCTION_TIMEOUT,
+    }
+
     this.settings = settings
     this.watch = watch === true
 
diff --git a/packages/functions/prod/src/lib/consts.test.ts b/packages/functions/prod/src/lib/consts.test.ts
new file mode 100644
index 00000000..6a52df1a
--- /dev/null
+++ b/packages/functions/prod/src/lib/consts.test.ts
@@ -0,0 +1,10 @@
+import { describe, expect, test } from 'vitest'
+
+import { BACKGROUND_FUNCTION_TIMEOUT, SYNCHRONOUS_FUNCTION_TIMEOUT } from './consts.js'
+
+describe('Function timeout constants', () => {
+  test('exports correct timeout values', () => {
+    expect(SYNCHRONOUS_FUNCTION_TIMEOUT).toBe(30)
+    expect(BACKGROUND_FUNCTION_TIMEOUT).toBe(900)
+  })
+})
diff --git a/packages/functions/prod/src/lib/consts.ts b/packages/functions/prod/src/lib/consts.ts
index b128f6e4..aa620278 100644
--- a/packages/functions/prod/src/lib/consts.ts
+++ b/packages/functions/prod/src/lib/consts.ts
@@ -3,4 +3,21 @@ const HTTP_STATUS_METHOD_NOT_ALLOWED = 405
 const HTTP_STATUS_OK = 200
 const METADATA_VERSION = 1
 
-export { BUILDER_FUNCTIONS_FLAG, HTTP_STATUS_METHOD_NOT_ALLOWED, HTTP_STATUS_OK, METADATA_VERSION }
+/**
+ * Default timeout for synchronous functions in seconds
+ */
+const SYNCHRONOUS_FUNCTION_TIMEOUT = 30
+
+/**
+ * Default timeout for background functions in seconds
+ */
+const BACKGROUND_FUNCTION_TIMEOUT = 900
+
+export {
+  BUILDER_FUNCTIONS_FLAG,
+  HTTP_STATUS_METHOD_NOT_ALLOWED,
+  HTTP_STATUS_OK,
+  METADATA_VERSION,
+  SYNCHRONOUS_FUNCTION_TIMEOUT,
+  BACKGROUND_FUNCTION_TIMEOUT,
+}
diff --git a/packages/functions/prod/src/main.ts b/packages/functions/prod/src/main.ts
index ac79a7fd..86ad080c 100644
--- a/packages/functions/prod/src/main.ts
+++ b/packages/functions/prod/src/main.ts
@@ -10,4 +10,5 @@ export { builder } from './lib/builder.js'
 export { purgeCache } from './lib/purge_cache.js'
 export { schedule } from './lib/schedule.js'
 export { stream } from './lib/stream.js'
+export { SYNCHRONOUS_FUNCTION_TIMEOUT, BACKGROUND_FUNCTION_TIMEOUT } from './lib/consts.js'
 export * from './function/index.js'
diff --git a/packages/types/src/main.ts b/packages/types/src/main.ts
index 6166a756..637d21b7 100644
--- a/packages/types/src/main.ts
+++ b/packages/types/src/main.ts
@@ -2,3 +2,4 @@ export type { Context } from './lib/context/context.js'
 export type { Cookie } from './lib/context/cookies.js'
 export type { EnvironmentVariables } from './lib/environment-variables.js'
 export type { NetlifyGlobal } from './lib/globals.js'
+export type { Site } from './lib/context/site.js'