diff --git a/components/calendar/__tests__/calendar-agenda-view.test.tsx b/components/calendar/__tests__/calendar-agenda-view.test.tsx
index f56572a56..c340e117a 100644
--- a/components/calendar/__tests__/calendar-agenda-view.test.tsx
+++ b/components/calendar/__tests__/calendar-agenda-view.test.tsx
@@ -169,4 +169,20 @@ describe('CalendarAgendaView infinite scroll', () => {
     const titles = screen.getAllByText(/^Event /).map((el) => el.textContent);
     expect(titles).toEqual(['Event sooner', 'Event later']);
   });
+
+  it('strikes through events the user declined (#1110)', () => {
+    const invite = (id: string, status: string) => ({
+      ...makeEvent(id, '2026-09-12T09:00:00'),
+      participants: {
+        me: { '@type': 'Participant', calendarAddress: 'mailto:me@example.com', participationStatus: status },
+      },
+    }) as unknown as CalendarEvent;
+    renderView({
+      events: [invite('declined', 'declined'), invite('accepted', 'accepted')],
+      currentUserEmails: ['me@example.com'],
+    });
+    expect(screen.getByText('Event declined')).toHaveClass('line-through');
+    expect(screen.getByText('Event declined').closest('button')).toHaveClass('opacity-60');
+    expect(screen.getByText('Event accepted')).not.toHaveClass('line-through');
+  });
 });
diff --git a/components/calendar/__tests__/event-card.test.tsx b/components/calendar/__tests__/event-card.test.tsx
new file mode 100644
index 000000000..27bbb69ac
--- /dev/null
+++ b/components/calendar/__tests__/event-card.test.tsx
@@ -0,0 +1,69 @@
+import { render, screen, cleanup } from '@testing-library/react';
+import { describe, it, expect, afterEach } from 'vitest';
+import { EventCard } from '../event-card';
+import type { CalendarEvent, CalendarParticipant } from '@/lib/jmap/types';
+
+// #1110: an invitation the user declined - the whole series or one occurrence
+// of an accepted series - stays on the calendar, struck through and dimmed
+// like a cancelled event, instead of looking like one they will attend.
+
+function makeOccurrence(id: string, myStatus: CalendarParticipant['participationStatus']): CalendarEvent {
+  return {
+    id,
+    '@type': 'Event',
+    uid: 'series',
+    title: 'Standup ' + id,
+    start: '2026-09-28T09:00:00',
+    duration: 'PT30M',
+    showWithoutTime: false,
+    status: 'confirmed',
+    calendarIds: { 'cal-1': true },
+    participants: {
+      org: { '@type': 'Participant', calendarAddress: 'mailto:boss@example.com', participationStatus: 'accepted' },
+      me: { '@type': 'Participant', calendarAddress: 'mailto:me@example.com', participationStatus: myStatus },
+    },
+  } as unknown as CalendarEvent;
+}
+
+const me = ['me@example.com'];
+
+describe('EventCard', () => {
+  afterEach(() => {
+    cleanup();
+  });
+
+  it.each(['chip', 'span', 'block'] as const)('strikes through an occurrence the user declined (%s)', (variant) => {
+    render(<EventCard event={makeOccurrence('a', 'declined')} variant={variant} currentUserEmails={me} />);
+    const card = screen.getByRole('button');
+    expect(card).toHaveClass('opacity-60');
+    expect(card.getAttribute('aria-label')).toMatch(/, participants\.declined$/);
+    expect(screen.getByText('Standup a')).toHaveClass('line-through');
+  });
+
+  it('leaves accepted and unanswered occurrences alone', () => {
+    render(
+      <>
+        <EventCard event={makeOccurrence('a', 'accepted')} variant="block" currentUserEmails={me} />
+        <EventCard event={makeOccurrence('b', 'needs-action')} variant="block" currentUserEmails={me} />
+      </>
+    );
+    for (const card of screen.getAllByRole('button')) {
+      expect(card).not.toHaveClass('opacity-60');
+      expect(card.getAttribute('aria-label')).not.toMatch(/declined/);
+    }
+    expect(screen.getByText('Standup a')).not.toHaveClass('line-through');
+  });
+
+  it('only looks at the user\'s own participant entry', () => {
+    const event = makeOccurrence('a', 'accepted');
+    event.participants!.org.participationStatus = 'declined';
+    render(<EventCard event={event} variant="block" currentUserEmails={me} />);
+    expect(screen.getByRole('button')).not.toHaveClass('opacity-60');
+  });
+
+  it('labels a cancelled event as cancelled even when the user declined it', () => {
+    const event = { ...makeOccurrence('a', 'declined'), status: 'cancelled' } as CalendarEvent;
+    render(<EventCard event={event} variant="block" currentUserEmails={me} />);
+    expect(screen.getByRole('button').getAttribute('aria-label')).toMatch(/, detail\.cancelled$/);
+  });
+});
diff --git a/components/calendar/calendar-agenda-view.tsx b/components/calendar/calendar-agenda-view.tsx
index 4c39cb2c3..fe9d84f81 100644
--- a/components/calendar/calendar-agenda-view.tsx
+++ b/components/calendar/calendar-agenda-view.tsx
@@ -9,7 +9,7 @@ import { cn } from "@/lib/utils";
 import { getEventColor } from "./event-card";
 import { getEventDayBounds, getEventEndDate, getEventStartDate, getPrimaryCalendarId } from "@/lib/calendar-utils";
 import { displayNow, isDisplayToday } from "@/lib/timezone";
-import { getParticipantCount } from "@/lib/calendar-participants";
+import { getParticipantCount, isDeclinedByUser } from "@/lib/calendar-participants";
 import { useScrollWindow } from "@/hooks/use-scroll-window";
 import type { ScrollWindowViewProps } from "@/lib/calendar-scroll-window";
 import type { CalendarEvent, Calendar } from "@/lib/jmap/types";
@@ -22,6 +22,8 @@ interface CalendarAgendaViewProps extends ScrollWindowViewProps {
   onHoverLeave?: () => void;
   onContextMenuEvent?: (e: React.MouseEvent, event: CalendarEvent) => void;
   timeFormat?: "12h" | "24h";
+  /** The user's calendar addresses, to mark events they declined (#1110). */
+  currentUserEmails?: string[];
 }
 
 interface DayGroup {
@@ -45,6 +47,7 @@ export function CalendarAgendaView({
   onHoverLeave,
   onContextMenuEvent,
   timeFormat = "24h",
+  currentUserEmails,
 }: CalendarAgendaViewProps) {
   const t = useTranslations("calendar");
   // Grid days / event dates are display dates (local fields = wall-clock in
@@ -207,8 +210,9 @@ export function CalendarAgendaView({
               const start = getEventStartDate(ev);
               const end = getEventEndDate(ev);
               // iTIP CANCEL marks the attendee's copy with status "cancelled"
-              // instead of deleting it (#572).
-              const isCancelled = ev.status === "cancelled";
+              // instead of deleting it (#572); a declined invitation stays
+              // listed too (#1110).
+              const isInactive = ev.status === "cancelled" || isDeclinedByUser(ev, currentUserEmails);
               const locationName = ev.locations
                 ? Object.values(ev.locations)[0]?.name
                 : null;
@@ -222,7 +226,7 @@ export function CalendarAgendaView({
                   onContextMenu={onContextMenuEvent ? (e) => onContextMenuEvent(e, ev) : undefined}
                   className={cn(
                     "w-full flex items-start px-4 hover:bg-muted/50 transition-colors text-start",
-                    isCancelled && "opacity-60"
+                    isInactive && "opacity-60"
                   )}
                   style={{ gap: 'var(--density-item-gap)', paddingBlock: 'var(--density-item-py)' }}
                 >
@@ -245,7 +249,7 @@ export function CalendarAgendaView({
                   />
 
                   <div className="flex-1 min-w-0">
-                    <div className={cn("text-sm font-medium truncate", isCancelled && "line-through")}>
+                    <div className={cn("text-sm font-medium truncate", isInactive && "line-through")}>
                       {ev.title || t("events.no_title")}
                     </div>
                     {locationName && (
diff --git a/components/calendar/calendar-app.tsx b/components/calendar/calendar-app.tsx
index c7b21de67..9bde310bf 100644
--- a/components/calendar/calendar-app.tsx
+++ b/components/calendar/calendar-app.tsx
@@ -1494,6 +1494,7 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
               tasks={calendarTasks}
               onToggleTaskComplete={handleToggleTaskComplete}
               onSelectTask={openEditTaskModal}
+              currentUserEmails={currentUserEmails}
             />
           );
         case "week":
@@ -1517,6 +1518,7 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
               tasks={calendarTasks}
               onToggleTaskComplete={handleToggleTaskComplete}
               onSelectTask={openEditTaskModal}
+              currentUserEmails={currentUserEmails}
             />
           );
         case "day":
@@ -1538,6 +1540,7 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
               tasks={calendarTasks}
               onToggleTaskComplete={handleToggleTaskComplete}
               onSelectTask={openEditTaskModal}
+              currentUserEmails={currentUserEmails}
             />
           );
         case "agenda":
@@ -1551,6 +1554,7 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
               onHoverLeave={handleHoverLeave}
               onContextMenuEvent={handleContextMenuEvent}
               timeFormat={timeFormat}
+              currentUserEmails={currentUserEmails}
             />
           );
         case "tasks":
diff --git a/components/calendar/calendar-day-view.tsx b/components/calendar/calendar-day-view.tsx
index 400a8edeb..7cf86fcab 100644
--- a/components/calendar/calendar-day-view.tsx
+++ b/components/calendar/calendar-day-view.tsx
@@ -33,6 +33,8 @@ interface CalendarDayViewProps extends ScrollWindowViewProps {
   tasks?: CalendarTask[];
   onToggleTaskComplete?: (task: CalendarTask) => void;
   onSelectTask?: (task: CalendarTask) => void;
+  /** The user's calendar addresses, to mark events they declined (#1110). */
+  currentUserEmails?: string[];
 }
 
 const HOUR_HEIGHT = 64;
@@ -63,6 +65,7 @@ export function CalendarDayView({
   tasks,
   onToggleTaskComplete,
   onSelectTask,
+  currentUserEmails,
 }: CalendarDayViewProps) {
   const t = useTranslations("calendar");
   // Grid days / event dates are display dates (local fields = wall-clock in
@@ -328,6 +331,7 @@ export function CalendarDayView({
                                   onMouseEnter={(rect) => onHoverEvent?.(ev, rect)}
                                   onMouseLeave={onHoverLeave}
                                   onContextMenu={onContextMenuEvent}
+                                  currentUserEmails={currentUserEmails}
                                 />
                               );
                             })}
@@ -456,6 +460,7 @@ export function CalendarDayView({
                             onMouseEnter={(rect) => onHoverEvent?.(ev, rect)}
                             onMouseLeave={onHoverLeave}
                             onContextMenu={onContextMenuEvent}
+                            currentUserEmails={currentUserEmails}
                             draggable
                           />
                           <div
diff --git a/components/calendar/calendar-month-view.tsx b/components/calendar/calendar-month-view.tsx
index ea285f34c..a81ad0640 100644
--- a/components/calendar/calendar-month-view.tsx
+++ b/components/calendar/calendar-month-view.tsx
@@ -8,6 +8,7 @@ import { EventCard } from "./event-card";
 import { CalendarTaskChip } from "./task-chip";
 import { buildWeekSegments, getEventDayBounds, getPrimaryCalendarId } from "@/lib/calendar-utils";
 import { groupTasksByDueDay } from "@/lib/calendar-tasks";
+import { isDeclinedByUser } from "@/lib/calendar-participants";
 import type { CalendarEvent, Calendar, CalendarTask } from "@/lib/jmap/types";
 import { useAuthStore } from "@/stores/auth-store";
 import { useCalendarStore } from "@/stores/calendar-store";
@@ -35,6 +36,8 @@ interface CalendarMonthViewProps extends ScrollWindowViewProps {
   tasks?: CalendarTask[];
   onToggleTaskComplete?: (task: CalendarTask) => void;
   onSelectTask?: (task: CalendarTask) => void;
+  /** The user's calendar addresses, to mark events they declined (#1110). */
+  currentUserEmails?: string[];
 }
 
 /** Fraction of the viewport height at which the "current month" is sampled. */
@@ -64,6 +67,7 @@ export function CalendarMonthView({
   tasks,
   onToggleTaskComplete,
   onSelectTask,
+  currentUserEmails,
 }: CalendarMonthViewProps) {
   const t = useTranslations("calendar");
   const showTimeInMonthView = useSettingsStore((state) => state.showTimeInMonthView);
@@ -344,10 +348,11 @@ export function CalendarMonthView({
                         const calId = getPrimaryCalendarId(ev);
                         const cal = calId ? calendarMap.get(calId) : undefined;
                         const evColor = ev.color || cal?.color || "#3b82f6";
+                        const inactive = ev.status === "cancelled" || isDeclinedByUser(ev, currentUserEmails);
                         return (
                           <span
                             key={ev.id}
-                            className="w-1.5 h-1.5 rounded-full"
+                            className={cn("w-1.5 h-1.5 rounded-full", inactive && "opacity-40")}
                             style={{ backgroundColor: evColor }}
                           />
                         );
@@ -436,6 +441,7 @@ export function CalendarMonthView({
                         onMouseEnter={(rect) => onHoverEvent?.(segment.event, rect)}
                         onMouseLeave={onHoverLeave}
                         onContextMenu={onContextMenuEvent}
+                        currentUserEmails={currentUserEmails}
                         draggable
                         className={isMobile ? "text-[10px] px-1" : undefined}
                       />
diff --git a/components/calendar/calendar-week-view.tsx b/components/calendar/calendar-week-view.tsx
index 093f65e4d..733bb2a5d 100644
--- a/components/calendar/calendar-week-view.tsx
+++ b/components/calendar/calendar-week-view.tsx
@@ -37,6 +37,8 @@ interface CalendarWeekViewProps extends ScrollWindowViewProps {
   tasks?: CalendarTask[];
   onToggleTaskComplete?: (task: CalendarTask) => void;
   onSelectTask?: (task: CalendarTask) => void;
+  /** The user's calendar addresses, to mark events they declined (#1110). */
+  currentUserEmails?: string[];
 }
 
 const HOUR_HEIGHT = 60;
@@ -70,6 +72,7 @@ export function CalendarWeekView({
   tasks,
   onToggleTaskComplete,
   onSelectTask,
+  currentUserEmails,
 }: CalendarWeekViewProps) {
   const t = useTranslations("calendar");
   // Grid days / event dates are display dates (local fields = wall-clock in
@@ -361,6 +364,7 @@ export function CalendarWeekView({
                       onMouseEnter={(rect) => onHoverEvent?.(segment.event, rect)}
                       onMouseLeave={onHoverLeave}
                       onContextMenu={onContextMenuEvent}
+                      currentUserEmails={currentUserEmails}
                     />
                   </div>
                 );
@@ -513,6 +517,7 @@ export function CalendarWeekView({
                           onMouseEnter={(rect) => onHoverEvent?.(ev, rect)}
                           onMouseLeave={onHoverLeave}
                           onContextMenu={onContextMenuEvent}
+                          currentUserEmails={currentUserEmails}
                           draggable
                         />
                         <div
diff --git a/components/calendar/event-card.tsx b/components/calendar/event-card.tsx
index 603fb38ca..6fb1447cb 100644
--- a/components/calendar/event-card.tsx
+++ b/components/calendar/event-card.tsx
@@ -6,7 +6,7 @@ import { cn } from "@/lib/utils";
 import type { CalendarEvent, Calendar } from "@/lib/jmap/types";
 import { format } from "date-fns";
 import { Users } from "@/components/icons";
-import { getParticipantCount } from "@/lib/calendar-participants";
+import { getParticipantCount, isDeclinedByUser } from "@/lib/calendar-participants";
 import { getEventEndDate, getEventStartDate } from "@/lib/calendar-utils";
 import { useSettingsStore } from "@/stores/settings-store";
 
@@ -24,6 +24,8 @@ interface EventCardProps {
   continuesAfter?: boolean;
   className?: string;
   style?: CSSProperties;
+  /** The user's calendar addresses, to tell whether they declined the event. */
+  currentUserEmails?: string[];
 }
 
 function sanitizeColor(color: string | null | undefined, fallback = "#3b82f6"): string {
@@ -71,7 +73,7 @@ function createEventDragPreview(title: string, timeRange: string, color: string)
   return el;
 }
 
-export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onMouseLeave, onContextMenu, isSelected, draggable: isDraggable, continuesAfter = false, className, style }: EventCardProps) {
+export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onMouseLeave, onContextMenu, isSelected, draggable: isDraggable, continuesAfter = false, className, style, currentUserEmails }: EventCardProps) {
   const t = useTranslations("calendar");
   const [isBeingDragged, setIsBeingDragged] = useState(false);
   const color = getEventColor(event, calendar);
@@ -89,9 +91,13 @@ export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onM
   };
   const timeString = `${safeFormat(startDate, timeFmt)} – ${safeFormat(endTime, timeFmt)}`;
   // iTIP CANCEL marks the attendee's copy with status "cancelled" instead of
-  // deleting it (#572) - render it struck through and dimmed.
+  // deleting it (#572), and a declined invitation stays on the calendar too
+  // (#1110) - render both struck through and dimmed.
   const isCancelled = event.status === "cancelled";
-  const ariaLabel = `${event.title || t("events.no_title")}, ${timeString}${calendarName ? `, ${calendarName}` : ""}${isCancelled ? `, ${t("detail.cancelled")}` : ""}`;
+  const isDeclined = !isCancelled && isDeclinedByUser(event, currentUserEmails);
+  const isInactive = isCancelled || isDeclined;
+  const statusLabel = isCancelled ? t("detail.cancelled") : isDeclined ? t("participants.declined") : null;
+  const ariaLabel = `${event.title || t("events.no_title")}, ${timeString}${calendarName ? `, ${calendarName}` : ""}${statusLabel ? `, ${statusLabel}` : ""}`;
 
   const handleDragStart = useCallback((e: DragEvent) => {
     e.stopPropagation();
@@ -139,7 +145,7 @@ export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onM
           "hover:opacity-80 transition-opacity",
           isSelected && "ring-2 ring-primary",
           isBeingDragged && "opacity-50",
-          isCancelled && !isBeingDragged && "opacity-60",
+          isInactive && !isBeingDragged && "opacity-60",
           className
         )}
         style={{ backgroundColor: `${color}20`, color, ...style }}
@@ -148,7 +154,7 @@ export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onM
           className="w-1.5 h-1.5 rounded-full flex-shrink-0"
           style={{ backgroundColor: color }}
         />
-        <span className={cn("truncate", isCancelled && "line-through")}>{event.title || t("events.no_title")}</span>
+        <span className={cn("truncate", isInactive && "line-through")}>{event.title || t("events.no_title")}</span>
       </button>
     );
   }
@@ -169,7 +175,7 @@ export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onM
           continuesAfter && "pe-2",
           isSelected && "ring-2 ring-primary",
           isBeingDragged && "opacity-50",
-          isCancelled && !isBeingDragged && "opacity-60",
+          isInactive && !isBeingDragged && "opacity-60",
           className
         )}
         style={{ backgroundColor: `${color}24`, borderLeft: `3px solid ${color}`, color, ...style }}
@@ -178,7 +184,7 @@ export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onM
           {showTimeInMonthView && !event.showWithoutTime && (
             <span className="flex-shrink-0 opacity-80">{format(startDate, timeFmt)}</span>
           )}
-          <span className={cn("truncate font-medium", isCancelled && "line-through")}>{event.title || t("events.no_title")}</span>
+          <span className={cn("truncate font-medium", isInactive && "line-through")}>{event.title || t("events.no_title")}</span>
         </div>
       </button>
     );
@@ -198,12 +204,12 @@ export function EventCard({ event, calendar, variant, onClick, onMouseEnter, onM
         "hover:opacity-90 transition-opacity cursor-pointer",
         isSelected && "ring-2 ring-primary",
         isBeingDragged && "opacity-50",
-        isCancelled && !isBeingDragged && "opacity-60",
+        isInactive && !isBeingDragged && "opacity-60",
         className
       )}
       style={{ backgroundColor: `${color}30`, borderLeft: `3px solid ${color}`, color, ...style }}
     >
-      <div className={cn("font-medium truncate", isCancelled && "line-through")}>{event.title || t("events.no_title")}</div>
+      <div className={cn("font-medium truncate", isInactive && "line-through")}>{event.title || t("events.no_title")}</div>
       {!event.showWithoutTime && (
         <div className="opacity-80 text-[10px]">
           {timeString}
diff --git a/lib/__tests__/calendar-participants.test.ts b/lib/__tests__/calendar-participants.test.ts
index ea340e93f..9169d9660 100644
--- a/lib/__tests__/calendar-participants.test.ts
+++ b/lib/__tests__/calendar-participants.test.ts
@@ -5,6 +5,7 @@ import {
   collectUserCalendarAddresses,
   getUserParticipantId,
   getUserStatus,
+  isDeclinedByUser,
   getParticipantList,
   getStatusCounts,
   getParticipantCount,
@@ -284,6 +285,29 @@ describe('getUserStatus', () => {
   });
 });
 
+describe('isDeclinedByUser', () => {
+  it("is true only for the user's own declined entry", () => {
+    const event = makeEvent({ att1: attendeeParticipant, dave: declinedAttendee });
+    expect(isDeclinedByUser(event, ['Dave@Example.com'])).toBe(true);
+    expect(isDeclinedByUser(event, ['bob@example.com'])).toBe(false);
+  });
+
+  it('matches the calendar address an occurrence override carries', () => {
+    // A reply to one occurrence comes back from Stalwart as an override
+    // participant with only a calendarAddress (#1110).
+    const event = makeEvent({
+      att: { '@type': 'Participant', calendarAddress: 'mailto:bob@example.com', participationStatus: 'declined' },
+    });
+    expect(isDeclinedByUser(event, ['alias@example.com', 'bob@example.com'])).toBe(true);
+  });
+
+  it('is false without user addresses or participants', () => {
+    expect(isDeclinedByUser(makeEvent({ dave: declinedAttendee }), [])).toBe(false);
+    expect(isDeclinedByUser(makeEvent({ dave: declinedAttendee }), undefined)).toBe(false);
+    expect(isDeclinedByUser(makeEvent(null), ['dave@example.com'])).toBe(false);
+  });
+});
+
 describe('getParticipantList', () => {
   it('returns all participants as info objects', () => {
     const event = makeEvent({
diff --git a/lib/calendar-participants.ts b/lib/calendar-participants.ts
index d7eae1066..25ebb9ffd 100644
--- a/lib/calendar-participants.ts
+++ b/lib/calendar-participants.ts
@@ -123,6 +123,15 @@ export function getUserStatus(
   return null;
 }
 
+/**
+ * True when the user declined this event. An occurrence carries its override's
+ * participants, so one declined instance of an accepted series counts (#1110).
+ */
+export function isDeclinedByUser(event: CalendarEvent, userEmails: string[] | undefined): boolean {
+  if (!userEmails || userEmails.length === 0) return false;
+  return getUserStatus(event, userEmails) === 'declined';
+}
+
 /** When the same address appears in two participant entries, a real RSVP on
  *  either one beats a missing/"needs-action" one — the duplicate is always the
  *  entry that never replied (the needs-action side). Between two real replies