diff --git a/src/tracker/index.test.ts b/src/tracker/index.test.ts
new file mode 100644
index 000000000..2e2fab59e
--- /dev/null
+++ b/src/tracker/index.test.ts
@@ -0,0 +1,38 @@
+import { afterEach, expect, test, vi } from 'vitest';
+
+afterEach(() => {
+  delete (window as Window & { umami?: unknown }).umami;
+  delete (document as Document & { currentScript?: HTMLScriptElement }).currentScript;
+  delete (document as Document & { readyState?: DocumentReadyState }).readyState;
+  vi.unstubAllGlobals();
+  vi.resetModules();
+});
+
+test('identifies data-distinct-id before the initial page view', async () => {
+  const script = document.createElement('script');
+  script.src = 'https://analytics.example.com/script.js';
+  script.dataset.websiteId = 'website-id';
+  script.dataset.distinctId = 'visitor-id';
+
+  Object.defineProperties(document, {
+    currentScript: { configurable: true, value: script },
+    readyState: { configurable: true, value: 'complete' },
+  });
+
+  const fetchMock = vi.fn().mockResolvedValue({ json: vi.fn().mockResolvedValue({}) });
+  vi.stubGlobal('fetch', fetchMock);
+
+  await import('./index');
+
+  await vi.waitFor(() => expect(fetchMock).toHaveBeenCalledTimes(2));
+  const requests = fetchMock.mock.calls.map(([, init]) => JSON.parse(init.body));
+
+  expect(requests[0]).toMatchObject({
+    type: 'identify',
+    payload: { id: 'visitor-id', website: 'website-id' },
+  });
+  expect(requests[1]).toMatchObject({
+    type: 'event',
+    payload: { id: 'visitor-id', website: 'website-id' },
+  });
+});
diff --git a/src/tracker/index.ts b/src/tracker/index.ts
index 1789d3363..588136b00 100644
--- a/src/tracker/index.ts
+++ b/src/tracker/index.ts
@@ -241,6 +241,7 @@ type MetricEntry = PerformanceEntry & {
   const website = config('website-id');
   const hostUrl = config('host-url');
   const beforeSend = config('before-send');
+  const distinctId = config('distinct-id') || undefined;
   const tag = config('tag') || undefined;
   const autoTrack = config('auto-track') !== _false;
   const dnt = config('do-not-track') === _true;
@@ -641,9 +642,13 @@ type MetricEntry = PerformanceEntry & {
   let initialized = false;
   let disabled = false;
   let cache: string | undefined;
-  let identity: string | undefined;
+  let identity = distinctId;
   let flushPerformance: (() => void) | undefined;
 
+  if (distinctId) {
+    void identify(distinctId);
+  }
+
   if (autoTrack && !trackingDisabled()) {
     if (document.readyState === 'complete') {
       init();