diff --git a/change/change-c213f895-ed17-4762-91fe-fc1225be29d6.json b/change/change-c213f895-ed17-4762-91fe-fc1225be29d6.json
new file mode 100644
index 00000000..3c36acd3
--- /dev/null
+++ b/change/change-c213f895-ed17-4762-91fe-fc1225be29d6.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "type": "patch",
+      "comment": "Add support for setting ESLINT_USE_FLAT_CONFIG to assist with upgrades to eslint v9",
+      "packageName": "just-scripts",
+      "email": "1581488+christiango@users.noreply.github.com",
+      "dependentChangeType": "patch"
+    }
+  ]
+}
diff --git a/packages/just-scripts/etc/just-scripts.api.md b/packages/just-scripts/etc/just-scripts.api.md
index 01f0d4c0..a4a219a8 100644
--- a/packages/just-scripts/etc/just-scripts.api.md
+++ b/packages/just-scripts/etc/just-scripts.api.md
@@ -213,6 +213,7 @@ export interface EsLintTaskOptions {
     // (undocumented)
     resolvePluginsPath?: string;
     timing?: boolean;
+    useFlatConfig?: boolean;
 }
 
 // @public (undocumented)
diff --git a/packages/just-scripts/src/tasks/eslintTask.ts b/packages/just-scripts/src/tasks/eslintTask.ts
index d79056ec..93b79c93 100644
--- a/packages/just-scripts/src/tasks/eslintTask.ts
+++ b/packages/just-scripts/src/tasks/eslintTask.ts
@@ -28,6 +28,11 @@ export interface EsLintTaskOptions {
   format?: string;
   /** Prevents the logging & auto-fixing of warnings */
   quiet?: boolean;
+  /**
+   * Can be set to force the flat config on or off, which can be helpful when migrating to ESLint v9.
+   * This will be passed as an environment variable to eslint with the value ESLINT_USE_FLAT_CONFIG (https://eslint.org/blog/2024/04/eslint-v9.0.0-released/#flat-config-is-now-the-default-and-has-some-changes).
+   */
+  useFlatConfig?: boolean;
 }
 
 export function eslintTask(options: EsLintTaskOptions = {}): TaskFunction {
@@ -47,6 +52,7 @@ export function eslintTask(options: EsLintTaskOptions = {}): TaskFunction {
       outputFile,
       format,
       quiet,
+      useFlatConfig,
     } = options;
     const eslintCmd = resolve('eslint/bin/eslint.js');
     // Try all possible extensions in the order listed here: https://eslint.org/docs/user-guide/configuring#configuration-file-formats
@@ -74,8 +80,18 @@ export function eslintTask(options: EsLintTaskOptions = {}): TaskFunction {
         '--color',
       ];
 
+      const env: Record<string, string> = {};
+
+      if (timing) {
+        env.TIMING = '1';
+      }
+
+      if (useFlatConfig !== undefined) {
+        env.ESLINT_USE_FLAT_CONFIG = JSON.stringify(useFlatConfig);
+      }
+
       logger.info(encodeArgs(eslintArgs).join(' '));
-      return spawn(process.execPath, eslintArgs, { stdio: 'inherit', ...(timing && { env: { TIMING: '1' } }) });
+      return spawn(process.execPath, eslintArgs, { stdio: 'inherit', env });
     } else {
       return Promise.resolve();
     }