diff --git a/backend/app/routers/events.py b/backend/app/routers/events.py
index e743f47..5a9525e 100644
--- a/backend/app/routers/events.py
+++ b/backend/app/routers/events.py
@@ -35,6 +35,7 @@ def _event_to_dict(
     display_calendar_name: str | None = None,
     display_calendar_color: str | None = None,
     can_modify: bool = False,
+    has_active_invitees: bool = False,
 ) -> dict:
     """Serialize a CalendarEvent ORM object to a response dict including calendar info."""
     # For invited events: use display calendar if set, otherwise fallback to "Invited"/gray
@@ -74,6 +75,7 @@ def _event_to_dict(
         "invitation_id": invitation_id,
         "display_calendar_id": display_calendar_id,
         "can_modify": can_modify,
+        "has_active_invitees": has_active_invitees,
     }
     return d
 
@@ -243,6 +245,21 @@ async def get_events(
     all_event_ids = [e.id for e in events]
     override_map = await get_invitation_overrides_for_user(db, current_user.id, all_event_ids)
 
+    # Batch-fetch event IDs that have accepted/tentative invitees (for owner's shared icon)
+    active_invitee_set: set[int] = set()
+    if all_event_ids:
+        active_inv_result = await db.execute(
+            select(EventInvitation.event_id).where(
+                EventInvitation.event_id.in_(all_event_ids),
+                EventInvitation.status.in_(["accepted", "tentative"]),
+            ).distinct()
+        )
+        active_invitee_set = {r[0] for r in active_inv_result.all()}
+        # Also mark parent events: if a parent has active invitees, all its children should show the icon
+        parent_ids = {e.parent_event_id for e in events if e.parent_event_id and e.parent_event_id in active_invitee_set}
+        if parent_ids:
+            active_invitee_set.update(e.id for e in events if e.parent_event_id in active_invitee_set)
+
     response: List[dict] = []
     for e in events:
         # Determine if this event is from an invitation
@@ -272,6 +289,7 @@ async def get_events(
             display_calendar_name=disp_cal_name,
             display_calendar_color=disp_cal_color,
             can_modify=inv_can_modify,
+            has_active_invitees=(parent_id in active_invitee_set or e.id in active_invitee_set),
         ))
 
     # Fetch the user's Birthdays system calendar; only generate virtual events if visible
diff --git a/frontend/src/components/calendar/CalendarPage.tsx b/frontend/src/components/calendar/CalendarPage.tsx
index 3cec58e..dc58d13 100644
--- a/frontend/src/components/calendar/CalendarPage.tsx
+++ b/frontend/src/components/calendar/CalendarPage.tsx
@@ -389,6 +389,7 @@ export default function CalendarPage() {
         calendarColor: event.calendar_color || 'hsl(var(--accent-color))',
         is_invited: event.is_invited,
         can_modify: event.can_modify,
+        has_active_invitees: event.has_active_invitees,
       },
     }));
 
@@ -531,6 +532,7 @@ export default function CalendarPage() {
     const isAllDay = arg.event.allDay;
     const isRecurring = arg.event.extendedProps.is_recurring || arg.event.extendedProps.parent_event_id;
     const isInvited = arg.event.extendedProps.is_invited;
+    const hasActiveInvitees = arg.event.extendedProps.has_active_invitees;
     const calColor = arg.event.extendedProps.calendarColor as string;
 
     // Sync --event-color on the parent FC element so CSS rules (background, hover)
@@ -544,7 +546,7 @@ export default function CalendarPage() {
 
     const icons = (
       <>
-        {isInvited && <Users className="h-2.5 w-2.5 shrink-0 opacity-60" />}
+        {(isInvited || hasActiveInvitees) && <Users className="h-2.5 w-2.5 shrink-0 opacity-60" />}
         {isRecurring && <Repeat className="h-2.5 w-2.5 shrink-0 opacity-50" />}
       </>
     );
diff --git a/frontend/src/types/index.ts b/frontend/src/types/index.ts
index 357a297..0bbc8d1 100644
--- a/frontend/src/types/index.ts
+++ b/frontend/src/types/index.ts
@@ -117,6 +117,7 @@ export interface CalendarEvent {
   invitation_id?: number | null;
   display_calendar_id?: number | null;
   can_modify?: boolean;
+  has_active_invitees?: boolean;
   created_at: string;
   updated_at: string;
 }