diff --git a/service-workers/service-worker/partitioned-cookies.tentative.https.html b/service-workers/service-worker/partitioned-cookies.tentative.https.html
new file mode 100644
index 00000000000000..ed0759de4c2f08
--- /dev/null
+++ b/service-workers/service-worker/partitioned-cookies.tentative.https.html
@@ -0,0 +1,85 @@
+<!DOCTYPE html>
+<meta charset="utf-8"/>
+<meta name="timeout" content="long">
+<title>Service Worker: Partitioned Cookies</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/test-helpers.sub.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+
+<!--
+  This test exercises partitioned service workers' interaction with partitioned cookies.
+  Partitioned service workers should only be able to interact with partitioned cookies whose
+  partition key matches the worker's partition.
+-->
+
+<body>
+</body>
+<script>
+
+promise_test(async t => {
+  const script = './resources/partitioned-cookies-sw.js'
+  const scope = './resources/partitioned-cookies-'
+  const absolute_scope = new URL(scope, window.location).href;
+
+  const reg = await service_worker_unregister_and_register(t, script, scope);
+  await wait_for_state(t, reg.installing, 'activated');
+  t.add_cleanup(() => reg.unregister());
+
+  // on_message will be reassigned below based on the expected reply from the service worker.
+  let on_message;
+  self.addEventListener('message', ev => on_message(ev));
+  navigator.serviceWorker.addEventListener('message', evt => {
+    self.postMessage(evt.data, '*');
+  });
+
+  let wait_promise;
+  let resolve_wait_promise;
+
+  const retrieved_registrations =
+        await navigator.serviceWorker.getRegistrations();
+  // It's possible that other tests have left behind other service workers.
+  // This steps filters those other SWs out.
+  const filtered_registrations =
+    retrieved_registrations.filter(reg => reg.scope == absolute_scope);
+
+  // First test that the worker script started correctly and message passing is enabed.
+  wait_promise = new Promise(resolve => {
+    resolve_wait_promise = resolve;
+  });
+  let got;
+  on_message = ev => {
+    got = ev.data;
+    resolve_wait_promise();
+  };
+  filtered_registrations[0].active.postMessage({type: 'test_message'});
+  await wait_promise;
+  assert_true(got.ok, 'Message passing');
+
+  // Set a Partitioned cookie.
+  document.cookie = '__Host-partitioned=123; Secure; Path=/; SameSite=None; Partitioned;';
+  assert_true(document.cookie.includes('__Host-partitioned=123'));
+
+  // Test that the partitioned cookie is available to this worker.
+  wait_promise = new Promise(resolve => {
+    resolve_wait_promise = resolve;
+  });
+  on_message = ev => {
+    got = ev.data;
+    resolve_wait_promise();
+  };
+  filtered_registrations[0].active.postMessage({type: 'echo_cookies'});
+  await wait_promise;
+  assert_true(got.ok, 'Get cookies');
+  assert_true(got.cookies.includes('__Host-partitioned'), 'Can access partitioned cookie');
+
+  const popup = window.open(
+      new URL(
+          `./resources/partitioned-cookies-3p-window.html?origin=${
+              encodeURIComponent(self.location.origin)}`,
+          get_host_info().HTTPS_NOTSAMESITE_ORIGIN + self.location.pathname));
+  await fetch_tests_from_window(popup);
+});
+
+</script>
+</html
\ No newline at end of file
diff --git a/service-workers/service-worker/resources/partitioned-cookies-3p-frame.html b/service-workers/service-worker/resources/partitioned-cookies-3p-frame.html
new file mode 100644
index 00000000000000..ec8f3a4703c86c
--- /dev/null
+++ b/service-workers/service-worker/resources/partitioned-cookies-3p-frame.html
@@ -0,0 +1,64 @@
+<!DOCTYPE html>
+<meta charset="utf-8"/>
+<meta name="timeout" content="long">
+<title>Service Worker: Partitioned Cookies 3P Iframe</title>
+<script src="/resources/testharness.js"></script>
+<script src="test-helpers.sub.js"></script>
+
+<body>
+</body>
+<script>
+
+promise_test(async t => {
+  const script = './partitioned-cookies-sw.js';
+  const scope = './partitioned-cookies-';
+  const absolute_scope = new URL(scope, window.location).href;
+
+  assert_false(document.cookie.includes('__Host-partitioned=123'), 'DOM cannot access partitioned cookie');
+
+  const reg = await service_worker_unregister_and_register(t, script, scope);
+  await wait_for_state(t, reg.installing, 'activated');
+
+  let retrieved_registrations =
+        await navigator.serviceWorker.getRegistrations();
+  let filtered_registrations =
+    retrieved_registrations.filter(reg => reg.scope == absolute_scope);
+
+  // on_message will be reassigned below based on the expected reply from the service worker.
+  let on_message;
+  self.addEventListener('message', ev => on_message(ev));
+  navigator.serviceWorker.addEventListener('message', evt => {
+    self.postMessage(evt.data, '*');
+  });
+
+  // First test that the worker script started correctly and message passing is enabed.
+  wait_promise = new Promise(resolve => {
+    resolve_wait_promise = resolve;
+  });
+  let got;
+  on_message = ev => {
+    got = ev.data;
+    resolve_wait_promise();
+  };
+  filtered_registrations[0].active.postMessage({type: 'test_message'});
+  await wait_promise;
+  assert_true(got.ok, 'Message passing');
+
+  // Test that the partitioned cookie is not available to this worker.
+  wait_promise = new Promise(resolve => {
+    resolve_wait_promise = resolve;
+  });
+  on_message = ev => {
+    got = ev.data;
+    resolve_wait_promise();
+  };
+  filtered_registrations[0].active.postMessage({type: 'echo_cookies'});
+  await wait_promise;
+  assert_true(got.ok, 'Get cookies');
+  assert_false(
+      got.cookies.includes('__Host-partitioned'),
+      'Worker annot access partitioned cookie');
+});
+
+</script>
+</html
\ No newline at end of file
diff --git a/service-workers/service-worker/resources/partitioned-cookies-3p-window.html b/service-workers/service-worker/resources/partitioned-cookies-3p-window.html
new file mode 100644
index 00000000000000..fd902fca827617
--- /dev/null
+++ b/service-workers/service-worker/resources/partitioned-cookies-3p-window.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<meta charset="utf-8"/>
+<meta name="timeout" content="long">
+<title>Service Worker: Partitioned Cookies 3P Window</title>
+<script src="/resources/testharness.js"></script>
+
+<body>
+</body>
+<script>
+
+promise_test(async t => {
+  assert_true(
+      location.search.includes('origin='), 'First party origin passed');
+  const first_party_origin = decodeURIComponent(
+      location.search.split('origin=')[1]);
+  const iframe = document.createElement('iframe');
+  iframe.src = new URL(
+      './partitioned-cookies-3p-frame.html',
+      first_party_origin + location.pathname).href;
+  document.body.appendChild(iframe);
+  fetch_tests_from_window(iframe.contentWindow);
+});
+
+</script>
+</html>
diff --git a/service-workers/service-worker/resources/partitioned-cookies-sw.js b/service-workers/service-worker/resources/partitioned-cookies-sw.js
new file mode 100644
index 00000000000000..2f54a984b19c45
--- /dev/null
+++ b/service-workers/service-worker/resources/partitioned-cookies-sw.js
@@ -0,0 +1,30 @@
+self.addEventListener('message', ev => ev.waitUntil(onMessage(ev)));
+
+async function onMessage(event) {
+  if (!event.data)
+    return;
+  switch (event.data.type) {
+    case 'test_message':
+      return onTestMessage(event);
+    case 'echo_cookies':
+      return onEchoCookies(event);
+    default:
+      return;
+  }
+}
+
+// test_message just verifies that the message passing is working.
+async function onTestMessage(event) {
+  event.source.postMessage({ok: true});
+}
+
+// echo_cookies returns the names of all of the cookies available to the worker.
+async function onEchoCookies(event) {
+  try {
+    const cookie_objects = await self.cookieStore.getAll();
+    const cookies = cookie_objects.map(c => c.name);
+    event.source.postMessage({ok: true, cookies});
+  } catch (err) {
+    event.source.postMessage({ok: false});
+  }
+}
