diff --git a/src/data/calendar.ts b/src/data/calendar.ts
index 819bbee25d..5e20205fee 100644
--- a/src/data/calendar.ts
+++ b/src/data/calendar.ts
@@ -56,13 +56,14 @@ export const fetchCalendarEvents = async (
   start: Date,
   end: Date,
   calendars: Calendar[]
-): Promise<CalendarEvent[]> => {
+): Promise<{ events: CalendarEvent[]; errors: string[] }> => {
   const params = encodeURI(
     `?start=${start.toISOString()}&end=${end.toISOString()}`
   );
 
   const calEvents: CalendarEvent[] = [];
-  const promises: Promise<any>[] = [];
+  const errors: string[] = [];
+  const promises: Promise<CalendarEvent[]>[] = [];
 
   calendars.forEach((cal) => {
     promises.push(
@@ -73,9 +74,15 @@ export const fetchCalendarEvents = async (
     );
   });
 
-  const results = await Promise.all(promises);
-
-  results.forEach((result, idx) => {
+  for (const [idx, promise] of promises.entries()) {
+    let result: CalendarEvent[];
+    try {
+      // eslint-disable-next-line no-await-in-loop
+      result = await promise;
+    } catch (err) {
+      errors.push(calendars[idx].entity_id);
+      continue;
+    }
     const cal = calendars[idx];
     result.forEach((ev) => {
       const eventStart = getCalendarDate(ev.start);
@@ -104,9 +111,9 @@ export const fetchCalendarEvents = async (
 
       calEvents.push(event);
     });
-  });
+  }
 
-  return calEvents;
+  return { events: calEvents, errors };
 };
 
 const getCalendarDate = (dateObj: any): string | undefined => {
diff --git a/src/panels/calendar/ha-full-calendar.ts b/src/panels/calendar/ha-full-calendar.ts
index 3cd139d303..90f6e3d4c4 100644
--- a/src/panels/calendar/ha-full-calendar.ts
+++ b/src/panels/calendar/ha-full-calendar.ts
@@ -97,6 +97,8 @@ export class HAFullCalendar extends LitElement {
 
   @property() public initialView: FullCalendarView = "dayGridMonth";
 
+  @property({ attribute: false }) public error?: string = undefined;
+
   private calendar?: Calendar;
 
   private _viewButtons?: ToggleButton[];
@@ -116,6 +118,14 @@ export class HAFullCalendar extends LitElement {
     return html`
       ${this.calendar
         ? html`
+            ${this.error
+              ? html`<ha-alert
+                  alert-type="error"
+                  dismissable
+                  @alert-dismissed-clicked=${this._clearError}
+                  >${this.error}</ha-alert
+                >`
+              : ""}
             <div class="header">
               ${!this.narrow
                 ? html`
@@ -380,6 +390,10 @@ export class HAFullCalendar extends LitElement {
     );
   });
 
+  private _clearError() {
+    this.error = undefined;
+  }
+
   static get styles(): CSSResultGroup {
     return [
       haStyle,
@@ -449,6 +463,11 @@ export class HAFullCalendar extends LitElement {
           z-index: 1;
         }
 
+        ha-alert {
+          display: block;
+          margin: 4px 0;
+        }
+
         #calendar {
           flex-grow: 1;
           background-color: var(
diff --git a/src/panels/calendar/ha-panel-calendar.ts b/src/panels/calendar/ha-panel-calendar.ts
index 5dc7a28381..de3410f3a8 100644
--- a/src/panels/calendar/ha-panel-calendar.ts
+++ b/src/panels/calendar/ha-panel-calendar.ts
@@ -15,6 +15,7 @@ import { customElement, property, state } from "lit/decorators";
 import { styleMap } from "lit/directives/style-map";
 import { LocalStorage } from "../../common/decorators/local-storage";
 import { HASSDomEvent } from "../../common/dom/fire_event";
+import { computeStateName } from "../../common/entity/compute_state_name";
 import "../../components/ha-card";
 import "../../components/ha-icon-button";
 import "../../components/ha-menu-button";
@@ -40,6 +41,8 @@ class PanelCalendar extends LitElement {
 
   @state() private _events: CalendarEvent[] = [];
 
+  @state() private _error?: string = undefined;
+
   @LocalStorage("deSelectedCalendars", true)
   private _deSelectedCalendars: string[] = [];
 
@@ -101,6 +104,7 @@ class PanelCalendar extends LitElement {
             .calendars=${this._calendars}
             .narrow=${this.narrow}
             .hass=${this.hass}
+            .error=${this._error}
             @view-changed=${this._handleViewChanged}
           ></ha-full-calendar>
         </div>
@@ -118,9 +122,9 @@ class PanelCalendar extends LitElement {
     start: Date,
     end: Date,
     calendars: Calendar[]
-  ): Promise<CalendarEvent[]> {
+  ): Promise<{ events: CalendarEvent[]; errors: string[] }> {
     if (!calendars.length) {
-      return [];
+      return { events: [], errors: [] };
     }
 
     return fetchCalendarEvents(this.hass, start, end, calendars);
@@ -135,8 +139,9 @@ class PanelCalendar extends LitElement {
       const checked = ev.target.checked;
 
       if (checked) {
-        const events = await this._fetchEvents(this._start!, this._end!, [cal]);
-        this._events = [...this._events, ...events];
+        const result = await this._fetchEvents(this._start!, this._end!, [cal]);
+        this._events = [...this._events, ...result.events];
+        this._handleErrors(result.errors);
         this._deSelectedCalendars = this._deSelectedCalendars.filter(
           (deCal) => deCal !== cal.entity_id
         );
@@ -161,19 +166,40 @@ class PanelCalendar extends LitElement {
   ): Promise<void> {
     this._start = ev.detail.start;
     this._end = ev.detail.end;
-    this._events = await this._fetchEvents(
+    const result = await this._fetchEvents(
       this._start,
       this._end,
       this._selectedCalendars
     );
+    this._events = result.events;
+    this._handleErrors(result.errors);
   }
 
   private async _handleRefresh(): Promise<void> {
-    this._events = await this._fetchEvents(
+    const result = await this._fetchEvents(
       this._start!,
       this._end!,
       this._selectedCalendars
     );
+    this._events = result.events;
+    this._handleErrors(result.errors);
+  }
+
+  private _handleErrors(error_entity_ids: string[]) {
+    this._error = undefined;
+    if (error_entity_ids.length > 0) {
+      const nameList = error_entity_ids
+        .map((error_entity_id) =>
+          this.hass!.states[error_entity_id]
+            ? computeStateName(this.hass!.states[error_entity_id])
+            : error_entity_id
+        )
+        .join(", ");
+
+      this._error = `${this.hass!.localize(
+        "ui.components.calendar.event_retrieval_error"
+      )} ${nameList}`;
+    }
   }
 
   static get styles(): CSSResultGroup {
diff --git a/src/panels/lovelace/cards/hui-calendar-card.ts b/src/panels/lovelace/cards/hui-calendar-card.ts
index 6b551746c3..f389f9388e 100644
--- a/src/panels/lovelace/cards/hui-calendar-card.ts
+++ b/src/panels/lovelace/cards/hui-calendar-card.ts
@@ -10,6 +10,7 @@ import { customElement, property, state, query } from "lit/decorators";
 import { getColorByIndex } from "../../../common/color/colors";
 import { applyThemesOnElement } from "../../../common/dom/apply_themes_on_element";
 import { HASSDomEvent } from "../../../common/dom/fire_event";
+import { computeStateName } from "../../../common/entity/compute_state_name";
 import { debounce } from "../../../common/util/debounce";
 import "../../../components/ha-card";
 import {
@@ -69,6 +70,8 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
 
   @state() private _veryNarrow = false;
 
+  @state() private _error?: string = undefined;
+
   @query("ha-full-calendar", true) private _calendar?: HAFullCalendar;
 
   private _startDate?: Date;
@@ -131,6 +134,7 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
           .hass=${this.hass}
           .views=${views}
           .initialView=${this._config.initial_view!}
+          .error=${this._error}
           @view-changed=${this._handleViewChanged}
         ></ha-full-calendar>
       </ha-card>
@@ -169,12 +173,28 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
       return;
     }
 
-    this._events = await fetchCalendarEvents(
+    this._error = undefined;
+    const result = await fetchCalendarEvents(
       this.hass!,
       this._startDate,
       this._endDate,
       this._calendars
     );
+    this._events = result.events;
+
+    if (result.errors.length > 0) {
+      const nameList = result.errors
+        .map((error_entity_id) =>
+          this.hass!.states[error_entity_id]
+            ? computeStateName(this.hass!.states[error_entity_id])
+            : error_entity_id
+        )
+        .join(", ");
+
+      this._error = `${this.hass!.localize(
+        "ui.components.calendar.event_retrieval_error"
+      )} ${nameList}`;
+    }
   }
 
   private _measureCard() {
diff --git a/src/translations/en.json b/src/translations/en.json
index ca6749cf87..34f5efdcc2 100755
--- a/src/translations/en.json
+++ b/src/translations/en.json
@@ -634,6 +634,7 @@
         "label": "Calendar",
         "my_calendars": "My Calendars",
         "today": "Today",
+        "event_retrieval_error": "Could not retrieve events for calendars: ",
         "event": {
           "add": "Add Event",
           "delete": "Delete Event",