diff --git a/lms/static/scripts/frontend_apps/api-types.ts b/lms/static/scripts/frontend_apps/api-types.ts
index 00c872ca7b..52eb0bbfb5 100644
--- a/lms/static/scripts/frontend_apps/api-types.ts
+++ b/lms/static/scripts/frontend_apps/api-types.ts
@@ -218,6 +218,14 @@ export type StudentWithMetrics = Student & {
  */
 export type StudentsMetricsResponse = {
   students: StudentWithMetrics[];
+
+  /**
+   * Indicates the last time the students roster was updated.
+   *
+   * `null` indicates we don't have roster data and the list is based on
+   * assignment launches.
+   */
+  last_updated: ISODateTime | null;
 };
 
 type AssignmentWithCourse = Assignment & {
diff --git a/lms/static/scripts/frontend_apps/components/RelativeTime.tsx b/lms/static/scripts/frontend_apps/components/RelativeTime.tsx
index 9f7ad1a5b5..c1f384a1ab 100644
--- a/lms/static/scripts/frontend_apps/components/RelativeTime.tsx
+++ b/lms/static/scripts/frontend_apps/components/RelativeTime.tsx
@@ -8,17 +8,29 @@ import { useEffect, useMemo, useState } from 'preact/hooks';
 export type RelativeTimeProps = {
   /** The reference date-time, in ISO format */
   dateTime: string;
+
+  /**
+   * Whether a `title` attribute with the absolute date should be added.
+   * Defaults to `true`.
+   */
+  withTitle?: boolean;
 };
 
 /**
  * Displays a date as a time relative to `now`, making sure it is updated at
  * appropriate intervals
  */
-export default function RelativeTime({ dateTime }: RelativeTimeProps) {
+export default function RelativeTime({
+  dateTime,
+  withTitle = true,
+}: RelativeTimeProps) {
   const [now, setNow] = useState(() => new Date());
   const absoluteDate = useMemo(
-    () => formatDateTime(dateTime, { includeWeekday: true }),
-    [dateTime],
+    () =>
+      withTitle
+        ? formatDateTime(dateTime, { includeWeekday: true })
+        : undefined,
+    [dateTime, withTitle],
   );
   const relativeDate = useMemo(
     () => formatRelativeDate(new Date(dateTime), now),
diff --git a/lms/static/scripts/frontend_apps/components/dashboard/AssignmentActivity.tsx b/lms/static/scripts/frontend_apps/components/dashboard/AssignmentActivity.tsx
index 9160900291..1c683963d7 100644
--- a/lms/static/scripts/frontend_apps/components/dashboard/AssignmentActivity.tsx
+++ b/lms/static/scripts/frontend_apps/components/dashboard/AssignmentActivity.tsx
@@ -1,4 +1,10 @@
-import { ClockIcon } from '@hypothesis/frontend-shared';
+import {
+  CautionIcon,
+  ClockIcon,
+  FileGenericIcon,
+  InfoIcon,
+  Link,
+} from '@hypothesis/frontend-shared';
 import classnames from 'classnames';
 import { useCallback, useMemo, useState } from 'preact/hooks';
 import { useLocation, useParams, useSearch } from 'wouter-preact';
@@ -17,7 +23,6 @@ import { courseURL } from '../../utils/dashboard/navigation';
 import { rootViewTitle } from '../../utils/dashboard/root-view-title';
 import { useDocumentTitle } from '../../utils/hooks';
 import { type QueryParams, replaceURLParams } from '../../utils/url';
-import RelativeTime from '../RelativeTime';
 import type {
   DashboardActivityFiltersProps,
   SegmentsType,
@@ -26,6 +31,7 @@ import DashboardActivityFilters from './DashboardActivityFilters';
 import DashboardBreadcrumbs from './DashboardBreadcrumbs';
 import FormattedDate from './FormattedDate';
 import GradeIndicator from './GradeIndicator';
+import LastSyncIndicator from './LastSyncIndicator';
 import type { OrderableActivityTableColumn } from './OrderableActivityTable';
 import OrderableActivityTable from './OrderableActivityTable';
 import StudentStatusBadge from './StudentStatusBadge';
@@ -203,6 +209,7 @@ export default function AssignmentActivity() {
                 },
               },
       ),
+      last_updated: students.data?.last_updated ?? null,
     });
   }, [students]);
 
@@ -275,20 +282,26 @@ export default function AssignmentActivity() {
                 },
               ]}
             />
-            {lastSync.data && (
-              <div
-                className="flex gap-x-1 items-center text-color-text-light"
-                data-testid="last-sync-date"
-              >
-                <ClockIcon />
-                Grades last synced:{' '}
-                {lastSync.data.finish_date ? (
-                  <RelativeTime dateTime={lastSync.data.finish_date} />
-                ) : (
-                  'syncing…'
-                )}
-              </div>
-            )}
+            <div className="flex gap-0.5">
+              {lastSync.data && (
+                <LastSyncIndicator
+                  icon={
+                    lastSync.data.status === 'failed' ? CautionIcon : ClockIcon
+                  }
+                  taskName="Grades"
+                  dateTime={lastSync.data.finish_date}
+                  data-testid="last-sync-date"
+                />
+              )}
+              {students.data?.last_updated && (
+                <LastSyncIndicator
+                  icon={FileGenericIcon}
+                  taskName="Roster"
+                  dateTime={students.data.last_updated}
+                  data-testid="last-roster-date"
+                />
+              )}
+            </div>
           </div>
         )}
         <div className="flex justify-between items-center">
@@ -415,6 +428,19 @@ export default function AssignmentActivity() {
           }
         }}
       />
+      {!students.isLoading && !students.data?.last_updated && (
+        <Link
+          variant="text-light"
+          classes="flex items-center gap-1"
+          href="https://web.hypothes.is/help/student-roster-displays-in-the-lms-reporting-dashboards/"
+          target="_blank"
+          data-testid="missing-roster-message"
+        >
+          <InfoIcon />
+          Full roster data for this assignment is not available. This only shows
+          students who have previously launched it.
+        </Link>
+      )}
     </div>
   );
 }
diff --git a/lms/static/scripts/frontend_apps/components/dashboard/LastSyncIndicator.tsx b/lms/static/scripts/frontend_apps/components/dashboard/LastSyncIndicator.tsx
new file mode 100644
index 0000000000..e757e32b25
--- /dev/null
+++ b/lms/static/scripts/frontend_apps/components/dashboard/LastSyncIndicator.tsx
@@ -0,0 +1,48 @@
+import type { IconComponent } from '@hypothesis/frontend-shared';
+import { formatDateTime } from '@hypothesis/frontend-shared';
+import classnames from 'classnames';
+import { useMemo } from 'preact/hooks';
+
+import type { ISODateTime } from '../../api-types';
+import RelativeTime from '../RelativeTime';
+
+export type LastSyncIndicatorProps = {
+  icon: IconComponent;
+  taskName: string;
+  dateTime: ISODateTime | null;
+};
+
+/**
+ * Represents the last time a task that syncs periodically happened
+ */
+export default function LastSyncIndicator({
+  icon: Icon,
+  taskName,
+  dateTime,
+}: LastSyncIndicatorProps) {
+  const absoluteDate = useMemo(
+    () =>
+      dateTime ? formatDateTime(dateTime, { includeWeekday: true }) : undefined,
+    [dateTime],
+  );
+
+  return (
+    <div
+      className={classnames(
+        'flex gap-x-1 items-center p-1.5',
+        'bg-grey-2 text-color-text-light cursor-default',
+        'first:rounded-l last:rounded-r',
+      )}
+      title={absoluteDate && `${taskName} last synced on ${absoluteDate}`}
+      data-testid="container"
+    >
+      <Icon />
+      <span className="font-bold">{taskName}:</span>
+      {dateTime ? (
+        <RelativeTime dateTime={dateTime} withTitle={false} />
+      ) : (
+        <span data-testid="syncing">syncing…</span>
+      )}
+    </div>
+  );
+}
diff --git a/lms/static/scripts/frontend_apps/components/dashboard/test/AssignmentActivity-test.js b/lms/static/scripts/frontend_apps/components/dashboard/test/AssignmentActivity-test.js
index 5224116218..d1e0ae55bc 100644
--- a/lms/static/scripts/frontend_apps/components/dashboard/test/AssignmentActivity-test.js
+++ b/lms/static/scripts/frontend_apps/components/dashboard/test/AssignmentActivity-test.js
@@ -668,15 +668,18 @@ describe('AssignmentActivity', () => {
       const wrapper = createComponent();
       act(() => wrapper.find('SyncGradesButton').props().onSyncScheduled());
 
-      assert.calledWith(fakeMutate, {
-        students: activeStudents.map(({ auto_grading_grade, ...rest }) => ({
-          ...rest,
-          auto_grading_grade: {
-            ...auto_grading_grade,
-            last_grade: auto_grading_grade.current_grade,
-          },
-        })),
-      });
+      assert.calledWith(
+        fakeMutate,
+        sinon.match({
+          students: activeStudents.map(({ auto_grading_grade, ...rest }) => ({
+            ...rest,
+            auto_grading_grade: {
+              ...auto_grading_grade,
+              last_grade: auto_grading_grade.current_grade,
+            },
+          })),
+        }),
+      );
     });
 
     [
@@ -713,17 +716,14 @@ describe('AssignmentActivity', () => {
       {
         data: null,
         shouldDisplayLastSyncInfo: false,
-        shouldDisplaySyncing: false,
       },
       {
         data: { status: 'scheduled' },
         shouldDisplayLastSyncInfo: true,
-        shouldDisplaySyncing: true,
       },
       {
         data: { status: 'in_progress' },
         shouldDisplayLastSyncInfo: true,
-        shouldDisplaySyncing: true,
       },
       {
         data: {
@@ -731,7 +731,6 @@ describe('AssignmentActivity', () => {
           finish_date: '2024-10-02T14:24:15.677924+00:00',
         },
         shouldDisplayLastSyncInfo: true,
-        shouldDisplaySyncing: false,
       },
       {
         data: {
@@ -739,9 +738,8 @@ describe('AssignmentActivity', () => {
           finish_date: '2024-10-02T14:24:15.677924+00:00',
         },
         shouldDisplayLastSyncInfo: true,
-        shouldDisplaySyncing: false,
       },
-    ].forEach(({ data, shouldDisplayLastSyncInfo, shouldDisplaySyncing }) => {
+    ].forEach(({ data, shouldDisplayLastSyncInfo }) => {
       it('displays the last time grades were synced', () => {
         fakeUsePolledAPIFetch.returns({
           data,
@@ -752,13 +750,30 @@ describe('AssignmentActivity', () => {
         const lastSyncDate = wrapper.find('[data-testid="last-sync-date"]');
 
         assert.equal(lastSyncDate.exists(), shouldDisplayLastSyncInfo);
+      });
+    });
 
-        if (shouldDisplayLastSyncInfo) {
-          assert.equal(
-            lastSyncDate.text().includes('syncing…'),
-            shouldDisplaySyncing,
-          );
-        }
+    [
+      { lastUpdated: undefined, shouldDisplayLastSyncInfo: false },
+      {
+        lastUpdated: '2024-10-02T14:24:15.677924+00:00',
+        shouldDisplayLastSyncInfo: true,
+      },
+    ].forEach(({ lastUpdated, shouldDisplayLastSyncInfo }) => {
+      it('displays the last time roster was synced', () => {
+        setUpFakeUseAPIFetch(activeAssignment, {
+          students: activeStudents,
+          last_updated: lastUpdated,
+        });
+
+        const wrapper = createComponent();
+        const lastSyncDate = wrapper.find('[data-testid="last-roster-date"]');
+        const missingRosterMessage = wrapper.find(
+          '[data-testid="missing-roster-message"]',
+        );
+
+        assert.equal(lastSyncDate.exists(), shouldDisplayLastSyncInfo);
+        assert.equal(missingRosterMessage.exists(), !shouldDisplayLastSyncInfo);
       });
     });
 
diff --git a/lms/static/scripts/frontend_apps/components/dashboard/test/LastSyncIndicator-test.js b/lms/static/scripts/frontend_apps/components/dashboard/test/LastSyncIndicator-test.js
new file mode 100644
index 0000000000..7d26716de6
--- /dev/null
+++ b/lms/static/scripts/frontend_apps/components/dashboard/test/LastSyncIndicator-test.js
@@ -0,0 +1,39 @@
+import { FileCodeIcon, formatDateTime } from '@hypothesis/frontend-shared';
+import { mount } from 'enzyme';
+
+import LastSyncIndicator from '../LastSyncIndicator';
+
+describe('LastSyncIndicator', () => {
+  function createComponent(dateTime) {
+    return mount(
+      <LastSyncIndicator
+        icon={FileCodeIcon}
+        taskName="task"
+        dateTime={dateTime}
+      />,
+    ).find('[data-testid="container"]');
+  }
+
+  [
+    { dateTime: null, expectedTitle: undefined },
+    {
+      dateTime: '2024-10-02T14:24:15.677924+00:00',
+      expectedTitle: `task last synced on ${formatDateTime('2024-10-02T14:24:15.677924+00:00', { includeWeekday: true })}`,
+    },
+  ].forEach(({ dateTime, expectedTitle }) => {
+    it('has title when dateTime is not null', () => {
+      const wrapper = createComponent(dateTime);
+      assert.equal(wrapper.prop('title'), expectedTitle);
+    });
+
+    it('shows syncing message when date time is null', () => {
+      const wrapper = createComponent(dateTime);
+      assert.equal(wrapper.exists('[data-testid="syncing"]'), !dateTime);
+    });
+
+    it('shows relative time when dateTime is not null', () => {
+      const wrapper = createComponent(dateTime);
+      assert.equal(wrapper.exists('RelativeTime'), !!dateTime);
+    });
+  });
+});
diff --git a/lms/static/scripts/frontend_apps/components/test/RelativeTime-test.js b/lms/static/scripts/frontend_apps/components/test/RelativeTime-test.js
index 8167ae25e7..721d191a45 100644
--- a/lms/static/scripts/frontend_apps/components/test/RelativeTime-test.js
+++ b/lms/static/scripts/frontend_apps/components/test/RelativeTime-test.js
@@ -32,17 +32,19 @@ describe('RelativeTime', () => {
     $imports.$restore();
   });
 
-  function createComponent() {
-    return mount(<RelativeTime dateTime={dateTime} />);
+  function createComponent(props = {}) {
+    return mount(<RelativeTime dateTime={dateTime} {...props} />);
   }
 
-  it('sets initial time values', () => {
-    const wrapper = createComponent();
-    const time = wrapper.find('time');
+  [{ withTitle: true }, { withTitle: false }].forEach(({ withTitle }) => {
+    it('sets initial time values', () => {
+      const wrapper = createComponent({ withTitle });
+      const time = wrapper.find('time');
 
-    assert.equal(time.prop('title'), 'absolute date');
-    assert.equal(time.prop('dateTime'), dateTime);
-    assert.equal(wrapper.text(), 'relative date');
+      assert.equal(time.prop('title'), withTitle ? 'absolute date' : undefined);
+      assert.equal(time.prop('dateTime'), dateTime);
+      assert.equal(wrapper.text(), 'relative date');
+    });
   });
 
   it('is updated after time passes', () => {