diff --git a/apps/oxlint/src-js/index.ts b/apps/oxlint/src-js/index.ts
index eaa7348ae1121..8aff3dcbe416f 100644
--- a/apps/oxlint/src-js/index.ts
+++ b/apps/oxlint/src-js/index.ts
@@ -15,3 +15,18 @@ export const defineRule = _defineRule;
  * @deprecated Import from `oxlint/plugins-dev` instead
  */
 export const RuleTester = _RuleTester;
+
+export { defineConfig } from "./package/config.ts";
+
+export type {
+  AllowWarnDeny,
+  OxlintEnv,
+  DummyRule,
+  DummyRuleMap,
+  ExternalPluginEntry,
+  OxlintGlobals,
+  RuleCategories,
+  ExternalPluginsConfig,
+  OxlintConfig,
+  OxlintOverride,
+} from "./package/config.ts";
diff --git a/apps/oxlint/src-js/package/config.ts b/apps/oxlint/src-js/package/config.ts
new file mode 100644
index 0000000000000..a859ed75ddc7b
--- /dev/null
+++ b/apps/oxlint/src-js/package/config.ts
@@ -0,0 +1,54 @@
+/*
+ * `defineConfig` helper and config types.
+ */
+
+import type { JsonObject, JsonValue } from "../plugins/json.ts";
+
+export type AllowWarnDeny = "off" | "warn" | "error" | 0 | 1 | 2;
+
+export type DummyRule = AllowWarnDeny | [AllowWarnDeny, ...JsonValue[]];
+
+export type DummyRuleMap = Record<string, DummyRule>;
+
+export type RuleCategories = Record<string, AllowWarnDeny>;
+export type OxlintGlobals = Record<
+  string,
+  "readonly" | "writable" | "off" | "readable" | "writeable" | boolean
+>;
+
+export type OxlintEnv = Record<string, boolean>;
+
+export type ExternalPluginEntry = string | { name: string; specifier: string };
+
+export type ExternalPluginsConfig = ExternalPluginEntry[] | null;
+
+export interface OxlintOverride {
+  files: string[];
+  env?: OxlintEnv;
+  globals?: OxlintGlobals;
+  plugins?: string[];
+  jsPlugins?: ExternalPluginsConfig;
+  rules?: DummyRuleMap;
+}
+
+export interface OxlintConfig {
+  plugins?: string[];
+  jsPlugins?: ExternalPluginsConfig;
+  categories?: RuleCategories;
+  rules?: DummyRuleMap;
+  settings?: JsonObject;
+  env?: OxlintEnv;
+  globals?: OxlintGlobals;
+  overrides?: OxlintOverride[];
+  ignorePatterns?: string[];
+}
+
+/**
+ * Define an Oxlint configuration with type inference.
+ *
+ * @param config - Oxlint configuration
+ * @returns Config unchanged
+ */
+export function defineConfig<T extends OxlintConfig>(config: T): T {
+  return config;
+}
diff --git a/apps/oxlint/test/fixtures/js_config_define_config/files/test.js b/apps/oxlint/test/fixtures/js_config_define_config/files/test.js
new file mode 100644
index 0000000000000..d4e2f029dd793
--- /dev/null
+++ b/apps/oxlint/test/fixtures/js_config_define_config/files/test.js
@@ -0,0 +1,3 @@
+debugger;
+if (x == 1) {
+}
diff --git a/apps/oxlint/test/fixtures/js_config_define_config/output.snap.md b/apps/oxlint/test/fixtures/js_config_define_config/output.snap.md
new file mode 100644
index 0000000000000..da3555aad9bcc
--- /dev/null
+++ b/apps/oxlint/test/fixtures/js_config_define_config/output.snap.md
@@ -0,0 +1,29 @@
+# Exit code
+1
+
+# stdout
+```
+  x eslint(no-debugger): `debugger` statement is not allowed
+   ,-[files/test.js:1:1]
+ 1 | debugger;
+   : ^^^^^^^^^
+ 2 | if (x == 1) {
+   `----
+  help: Remove the debugger statement
+
+  ! eslint(eqeqeq): Expected === and instead saw ==
+   ,-[files/test.js:2:7]
+ 1 | debugger;
+ 2 | if (x == 1) {
+   :       ^^
+ 3 | }
+   `----
+  help: Prefer === operator
+
+Found 1 warning and 1 error.
+Finished in Xms on 1 file with 92 rules using X threads.
+```
+
+# stderr
+```
+```
diff --git a/apps/oxlint/test/fixtures/js_config_define_config/oxlint.config.ts b/apps/oxlint/test/fixtures/js_config_define_config/oxlint.config.ts
new file mode 100644
index 0000000000000..551ed0da6e47f
--- /dev/null
+++ b/apps/oxlint/test/fixtures/js_config_define_config/oxlint.config.ts
@@ -0,0 +1,8 @@
+import { defineConfig } from "#oxlint";
+
+export default defineConfig({
+  rules: {
+    "no-debugger": "error",
+    eqeqeq: "warn",
+  },
+});