diff --git a/.changeset/gentle-local-profiles.md b/.changeset/gentle-local-profiles.md
new file mode 100644
index 000000000..19c1e3f40
--- /dev/null
+++ b/.changeset/gentle-local-profiles.md
@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": patch
+---
+
+Pass local browser profile directories as Chrome flags instead of chrome-launcher options.
diff --git a/packages/core/lib/v3/launch/local.ts b/packages/core/lib/v3/launch/local.ts
index 7e23bc87a..d61f93e53 100644
--- a/packages/core/lib/v3/launch/local.ts
+++ b/packages/core/lib/v3/launch/local.ts
@@ -51,6 +51,7 @@ export async function launchLocalChrome(
     opts.ignoreHTTPSErrors ? "--ignore-certificate-errors" : undefined,
     opts.proxy?.server ? `--proxy-server=${opts.proxy.server}` : undefined,
     opts.proxy?.bypass ? `--proxy-bypass-list=${opts.proxy.bypass}` : undefined,
+    opts.userDataDir ? `--user-data-dir=${opts.userDataDir}` : undefined,
     ...(opts.args ?? []),
   ].filter((f): f is string => typeof f === "string");
 
@@ -76,7 +77,6 @@ export async function launchLocalChrome(
     chromePath: opts.executablePath,
     chromeFlags,
     port: opts.port,
-    userDataDir: opts.userDataDir,
     handleSIGINT: opts.handleSIGINT,
     ignoreDefaultFlags,
     connectionPollInterval,
diff --git a/packages/core/tests/unit/launch-local-ignore-default-args.test.ts b/packages/core/tests/unit/launch-local-ignore-default-args.test.ts
index d87d5dc3f..98f08ddec 100644
--- a/packages/core/tests/unit/launch-local-ignore-default-args.test.ts
+++ b/packages/core/tests/unit/launch-local-ignore-default-args.test.ts
@@ -71,9 +71,11 @@ afterEach(() => {
   vi.unstubAllGlobals();
 });
 
-async function getLaunchArgs(
-  opts: Record<string, unknown>,
-): Promise<{ chromeFlags: string[]; ignoreDefaultFlags: boolean }> {
+async function getLaunchArgs(opts: Record<string, unknown>): Promise<{
+  chromeFlags: string[];
+  ignoreDefaultFlags: boolean;
+  userDataDir?: string;
+}> {
   const { launchLocalChrome } = await import("../../lib/v3/launch/local.js");
   await launchLocalChrome(opts);
   return launchMock.mock.calls[0][0];
@@ -214,4 +216,15 @@ describe("launchLocalChrome ignoreDefaultArgs", () => {
     expect(args.chromeFlags).toContain("--renderer-process-limit=6");
     expect(args.chromeFlags).toContain("--remote-allow-origins=*");
   });
+
+  it("passes userDataDir as a Chrome flag instead of a chrome-launcher option", async () => {
+    const args = await getLaunchArgs({
+      userDataDir: "/home/user/project/chrome-profile",
+    });
+
+    expect(args.userDataDir).toBeUndefined();
+    expect(args.chromeFlags).toContain(
+      "--user-data-dir=/home/user/project/chrome-profile",
+    );
+  });
 });