diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 01ac28ba85..b88780278a 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -1658,6 +1658,22 @@
     "messageformat": "Pin",
     "description": "Message > Context Menu > Pin Message > Dialog > Pin Button"
   },
+  "icu:PinMessageDialog--HasMaxPinnedMessages__Title": {
+    "messageformat": "Replace oldest pin?",
+    "description": "Message > Context Menu > Pin Message (when at max pinned messages) > Dialog > Title"
+  },
+  "icu:PinMessageDialog--HasMaxPinnedMessages__Description": {
+    "messageformat": "Pinning this message will replace the oldest one.",
+    "description": "Message > Context Menu > Pin Message (when at max pinned messages) > Dialog > Description"
+  },
+  "icu:PinMessageDialog--HasMaxPinnedMessages__Cancel": {
+    "messageformat": "Cancel",
+    "description": "Message > Context Menu > Pin Message (when at max pinned messages) > Dialog > Cancel Button"
+  },
+  "icu:PinMessageDialog--HasMaxPinnedMessages__Continue": {
+    "messageformat": "Continue",
+    "description": "Message > Context Menu > Pin Message (when at max pinned messages) > Dialog > Continue Button"
+  },
   "icu:PinnedMessagesBar__AccessibilityLabel": {
     "messageformat": "{pinsCount, plural, one {Pinned message} other {Pinned messages}}",
     "description": "Conversation > With pinned message(s) > Pinned messages bar > Accessibility label"
diff --git a/ts/axo/AxoAlertDialog.dom.tsx b/ts/axo/AxoAlertDialog.dom.tsx
index 654cedfc84..514cbcd7eb 100644
--- a/ts/axo/AxoAlertDialog.dom.tsx
+++ b/ts/axo/AxoAlertDialog.dom.tsx
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import { AlertDialog } from 'radix-ui';
-import type { FC, ReactNode } from 'react';
+import type { FC, MouseEvent, ReactNode } from 'react';
 import React, { memo } from 'react';
 import { AxoButton } from './AxoButton.dom.js';
 import { tw } from './tw.dom.js';
@@ -221,7 +221,7 @@ export namespace AxoAlertDialog {
     variant: ActionVariant;
     symbol?: AxoSymbol.InlineGlyphName;
     arrow?: boolean;
-    onClick: () => void;
+    onClick: (event: MouseEvent<HTMLButtonElement>) => void;
     children: ReactNode;
   }>;
 
diff --git a/ts/components/conversation/Quote.dom.stories.tsx b/ts/components/conversation/Quote.dom.stories.tsx
index 93553c0c67..7d4f579dbe 100644
--- a/ts/components/conversation/Quote.dom.stories.tsx
+++ b/ts/components/conversation/Quote.dom.stories.tsx
@@ -98,6 +98,7 @@ const defaultMessageProps: TimelineMessagesProps = {
     'default--doubleCheckMissingQuoteReference'
   ),
   getPreferredBadge: () => undefined,
+  hasMaxPinnedMessages: false,
   i18n,
   platform: 'darwin',
   id: 'messageId',
diff --git a/ts/components/conversation/Timeline.dom.stories.tsx b/ts/components/conversation/Timeline.dom.stories.tsx
index 4c7dd1e682..ceedfd4bcd 100644
--- a/ts/components/conversation/Timeline.dom.stories.tsx
+++ b/ts/components/conversation/Timeline.dom.stories.tsx
@@ -66,6 +66,7 @@ function mockMessageTimelineItem(
       direction: 'incoming',
       status: 'sent',
       text: 'Hello there from the new world!',
+      hasMaxPinnedMessages: false,
       isBlocked: false,
       isMessageRequestAccepted: true,
       isPinned: false,
diff --git a/ts/components/conversation/TimelineMessage.dom.stories.tsx b/ts/components/conversation/TimelineMessage.dom.stories.tsx
index 43c133a8a0..1aefe19c21 100644
--- a/ts/components/conversation/TimelineMessage.dom.stories.tsx
+++ b/ts/components/conversation/TimelineMessage.dom.stories.tsx
@@ -265,6 +265,7 @@ const createProps = (overrideProps: Partial<Props> = {}): Props => ({
   expirationTimestamp: overrideProps.expirationTimestamp ?? 0,
   getPreferredBadge: overrideProps.getPreferredBadge || (() => undefined),
   giftBadge: overrideProps.giftBadge,
+  hasMaxPinnedMessages: false,
   i18n,
   platform: 'darwin',
   id: overrideProps.id ?? 'random-message-id',
diff --git a/ts/components/conversation/TimelineMessage.dom.tsx b/ts/components/conversation/TimelineMessage.dom.tsx
index 5f13e4bdf5..54590ecfe3 100644
--- a/ts/components/conversation/TimelineMessage.dom.tsx
+++ b/ts/components/conversation/TimelineMessage.dom.tsx
@@ -55,6 +55,7 @@ export type PropsData = {
   canReact: boolean;
   canReply: boolean;
   canPinMessages: boolean;
+  hasMaxPinnedMessages: boolean;
   selectedReaction?: string;
   isTargeted?: boolean;
 } & Omit<MessagePropsData, 'renderingContext' | 'menu'>;
@@ -118,6 +119,7 @@ export function TimelineMessage(props: Props): JSX.Element {
     containerWidthBreakpoint,
     conversationId,
     direction,
+    hasMaxPinnedMessages,
     i18n,
     id,
     interactivity,
@@ -493,6 +495,7 @@ export function TimelineMessage(props: Props): JSX.Element {
         open={pinMessageDialogOpen}
         onOpenChange={setPinMessageDialogOpen}
         onPinnedMessageAdd={handlePinnedMessageAdd}
+        hasMaxPinnedMessages={hasMaxPinnedMessages}
       />
     </>
   );
diff --git a/ts/components/conversation/pinned-messages/PinMessageDialog.dom.stories.tsx b/ts/components/conversation/pinned-messages/PinMessageDialog.dom.stories.tsx
index ea0142ebee..3b6f59d75c 100644
--- a/ts/components/conversation/pinned-messages/PinMessageDialog.dom.stories.tsx
+++ b/ts/components/conversation/pinned-messages/PinMessageDialog.dom.stories.tsx
@@ -20,6 +20,7 @@ export function Default(): JSX.Element {
       onOpenChange={setOpen}
       messageId="42"
       onPinnedMessageAdd={action('onPinnedMessageAdd')}
+      hasMaxPinnedMessages={false}
     />
   );
 }
diff --git a/ts/components/conversation/pinned-messages/PinMessageDialog.dom.tsx b/ts/components/conversation/pinned-messages/PinMessageDialog.dom.tsx
index bdb11f61fa..a25588793d 100644
--- a/ts/components/conversation/pinned-messages/PinMessageDialog.dom.tsx
+++ b/ts/components/conversation/pinned-messages/PinMessageDialog.dom.tsx
@@ -1,11 +1,13 @@
 // Copyright 2025 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
+import type { MouseEvent } from 'react';
 import React, { memo, useCallback, useState } from 'react';
 import { AxoDialog } from '../../../axo/AxoDialog.dom.js';
 import type { LocalizerType } from '../../../types/I18N.std.js';
 import { AxoRadioGroup } from '../../../axo/AxoRadioGroup.dom.js';
 import { DurationInSeconds } from '../../../util/durations/duration-in-seconds.std.js';
 import { strictAssert } from '../../../util/assert.std.js';
+import { AxoAlertDialog } from '../../../axo/AxoAlertDialog.dom.js';
 
 enum DurationOption {
   TIME_24_HOURS = 'TIME_24_HOURS',
@@ -30,6 +32,7 @@ export type PinMessageDialogProps = Readonly<{
   open: boolean;
   onOpenChange: (open: boolean) => void;
   messageId: string;
+  hasMaxPinnedMessages: boolean;
   onPinnedMessageAdd: (
     messageId: string,
     duration: DurationInSeconds | null
@@ -41,6 +44,23 @@ export const PinMessageDialog = memo(function PinMessageDialog(
 ) {
   const { i18n, messageId, onPinnedMessageAdd, onOpenChange } = props;
   const [duration, setDuration] = useState(DurationOption.TIME_7_DAYS);
+  const [confirmedReplaceOldestPin, setConfirmedReplaceOldestPin] =
+    useState(false);
+
+  const handleOpenChange = useCallback(
+    (open: boolean) => {
+      onOpenChange(open);
+      // reset state
+      setConfirmedReplaceOldestPin(false);
+      setDuration(DurationOption.TIME_7_DAYS);
+    },
+    [onOpenChange]
+  );
+
+  const handleConfirmReplaceOldestPin = useCallback((event: MouseEvent) => {
+    event.preventDefault();
+    setConfirmedReplaceOldestPin(true);
+  }, []);
 
   const handleValueChange = useCallback((value: string) => {
     strictAssert(isValidDurationOption(value), `Invalid option: ${value}`);
@@ -48,72 +68,107 @@ export const PinMessageDialog = memo(function PinMessageDialog(
   }, []);
 
   const handleCancel = useCallback(() => {
-    onOpenChange(false);
-  }, [onOpenChange]);
+    handleOpenChange(false);
+  }, [handleOpenChange]);
 
   const handlePinnedMessageAdd = useCallback(() => {
     const durationValue = DURATION_OPTIONS[duration];
     onPinnedMessageAdd(messageId, durationValue);
   }, [duration, onPinnedMessageAdd, messageId]);
 
+  const showConfirmReplaceOldestPin =
+    props.hasMaxPinnedMessages && !confirmedReplaceOldestPin;
+
   return (
-    <AxoDialog.Root open={props.open} onOpenChange={onOpenChange}>
-      <AxoDialog.Content
-        size="sm"
-        escape="cancel-is-noop"
-        disableMissingAriaDescriptionWarning
+    <>
+      <AxoAlertDialog.Root
+        open={props.open && showConfirmReplaceOldestPin}
+        onOpenChange={handleOpenChange}
       >
-        <AxoDialog.Header>
-          <AxoDialog.Title>
-            {i18n('icu:PinMessageDialog__Title')}
-          </AxoDialog.Title>
-          <AxoDialog.Close aria-label={i18n('icu:PinMessageDialog__Close')} />
-        </AxoDialog.Header>
-        <AxoDialog.Body>
-          <AxoRadioGroup.Root
-            value={duration}
-            onValueChange={handleValueChange}
-          >
-            <AxoRadioGroup.Item value={DurationOption.TIME_24_HOURS}>
-              <AxoRadioGroup.Indicator />
-              <AxoRadioGroup.Label>
-                {i18n('icu:PinMessageDialog__Option--TIME_24_HOURS')}
-              </AxoRadioGroup.Label>
-            </AxoRadioGroup.Item>
-            <AxoRadioGroup.Item value={DurationOption.TIME_7_DAYS}>
-              <AxoRadioGroup.Indicator />
-              <AxoRadioGroup.Label>
-                {i18n('icu:PinMessageDialog__Option--TIME_7_DAYS')}
-              </AxoRadioGroup.Label>
-            </AxoRadioGroup.Item>
-            <AxoRadioGroup.Item value={DurationOption.TIME_30_DAYS}>
-              <AxoRadioGroup.Indicator />
-              <AxoRadioGroup.Label>
-                {i18n('icu:PinMessageDialog__Option--TIME_30_DAYS')}
-              </AxoRadioGroup.Label>
-            </AxoRadioGroup.Item>
-            <AxoRadioGroup.Item value={DurationOption.FOREVER}>
-              <AxoRadioGroup.Indicator />
-              <AxoRadioGroup.Label>
-                {i18n('icu:PinMessageDialog__Option--FOREVER')}
-              </AxoRadioGroup.Label>
-            </AxoRadioGroup.Item>
-          </AxoRadioGroup.Root>
-        </AxoDialog.Body>
-        <AxoDialog.Footer>
-          <AxoDialog.Actions>
-            <AxoDialog.Action variant="secondary" onClick={handleCancel}>
-              {i18n('icu:PinMessageDialog__Cancel')}
-            </AxoDialog.Action>
-            <AxoDialog.Action
+        <AxoAlertDialog.Content escape="cancel-is-noop">
+          <AxoAlertDialog.Body>
+            <AxoAlertDialog.Title>
+              {i18n('icu:PinMessageDialog--HasMaxPinnedMessages__Title')}
+            </AxoAlertDialog.Title>
+            <AxoAlertDialog.Description>
+              {i18n('icu:PinMessageDialog--HasMaxPinnedMessages__Description')}
+            </AxoAlertDialog.Description>
+          </AxoAlertDialog.Body>
+          <AxoAlertDialog.Footer>
+            <AxoAlertDialog.Cancel>
+              {i18n('icu:PinMessageDialog--HasMaxPinnedMessages__Cancel')}
+            </AxoAlertDialog.Cancel>
+            <AxoAlertDialog.Action
               variant="primary"
-              onClick={handlePinnedMessageAdd}
+              onClick={handleConfirmReplaceOldestPin}
             >
-              {i18n('icu:PinMessageDialog__Pin')}
-            </AxoDialog.Action>
-          </AxoDialog.Actions>
-        </AxoDialog.Footer>
-      </AxoDialog.Content>
-    </AxoDialog.Root>
+              {i18n('icu:PinMessageDialog--HasMaxPinnedMessages__Continue')}
+            </AxoAlertDialog.Action>
+          </AxoAlertDialog.Footer>
+        </AxoAlertDialog.Content>
+      </AxoAlertDialog.Root>
+
+      <AxoDialog.Root
+        open={props.open && !showConfirmReplaceOldestPin}
+        onOpenChange={handleOpenChange}
+      >
+        <AxoDialog.Content
+          size="sm"
+          escape="cancel-is-noop"
+          disableMissingAriaDescriptionWarning
+        >
+          <AxoDialog.Header>
+            <AxoDialog.Title>
+              {i18n('icu:PinMessageDialog__Title')}
+            </AxoDialog.Title>
+            <AxoDialog.Close aria-label={i18n('icu:PinMessageDialog__Close')} />
+          </AxoDialog.Header>
+          <AxoDialog.Body>
+            <AxoRadioGroup.Root
+              value={duration}
+              onValueChange={handleValueChange}
+            >
+              <AxoRadioGroup.Item value={DurationOption.TIME_24_HOURS}>
+                <AxoRadioGroup.Indicator />
+                <AxoRadioGroup.Label>
+                  {i18n('icu:PinMessageDialog__Option--TIME_24_HOURS')}
+                </AxoRadioGroup.Label>
+              </AxoRadioGroup.Item>
+              <AxoRadioGroup.Item value={DurationOption.TIME_7_DAYS}>
+                <AxoRadioGroup.Indicator />
+                <AxoRadioGroup.Label>
+                  {i18n('icu:PinMessageDialog__Option--TIME_7_DAYS')}
+                </AxoRadioGroup.Label>
+              </AxoRadioGroup.Item>
+              <AxoRadioGroup.Item value={DurationOption.TIME_30_DAYS}>
+                <AxoRadioGroup.Indicator />
+                <AxoRadioGroup.Label>
+                  {i18n('icu:PinMessageDialog__Option--TIME_30_DAYS')}
+                </AxoRadioGroup.Label>
+              </AxoRadioGroup.Item>
+              <AxoRadioGroup.Item value={DurationOption.FOREVER}>
+                <AxoRadioGroup.Indicator />
+                <AxoRadioGroup.Label>
+                  {i18n('icu:PinMessageDialog__Option--FOREVER')}
+                </AxoRadioGroup.Label>
+              </AxoRadioGroup.Item>
+            </AxoRadioGroup.Root>
+          </AxoDialog.Body>
+          <AxoDialog.Footer>
+            <AxoDialog.Actions>
+              <AxoDialog.Action variant="secondary" onClick={handleCancel}>
+                {i18n('icu:PinMessageDialog__Cancel')}
+              </AxoDialog.Action>
+              <AxoDialog.Action
+                variant="primary"
+                onClick={handlePinnedMessageAdd}
+              >
+                {i18n('icu:PinMessageDialog__Pin')}
+              </AxoDialog.Action>
+            </AxoDialog.Actions>
+          </AxoDialog.Footer>
+        </AxoDialog.Content>
+      </AxoDialog.Root>
+    </>
   );
 });
diff --git a/ts/state/selectors/message.preload.ts b/ts/state/selectors/message.preload.ts
index 4219ee7c9f..2b3094a55b 100644
--- a/ts/state/selectors/message.preload.ts
+++ b/ts/state/selectors/message.preload.ts
@@ -170,6 +170,7 @@ import type { PinnedMessageNotificationData } from '../../components/conversatio
 import { canEditGroupInfo } from '../../util/canEditGroupInfo.preload.js';
 import { getPinnedMessagesMessageIds } from './pinnedMessages.dom.js';
 import { isPinnedMessagesSendEnabled } from '../../util/isPinnedMessagesEnabled.dom.js';
+import { getPinnedMessagesLimit } from '../../util/pinnedMessages.dom.js';
 
 const { groupBy, isEmpty, isNumber, isObject, map } = lodash;
 
@@ -966,6 +967,9 @@ export const getPropsForMessage = (
       expirationStartTimestamp,
     }),
     giftBadge: message.giftBadge,
+    hasMaxPinnedMessages: getHasMaxPinnedMessages(
+      options.pinnedMessagesMessageIds ?? []
+    ),
     poll: getPollForMessage(message, {
       conversationSelector: options.conversationSelector,
       ourConversationId,
@@ -2410,6 +2414,14 @@ export function canPinMessages(conversation: ConversationType): boolean {
   return conversation.type === 'direct' || canEditGroupInfo(conversation);
 }
 
+function getHasMaxPinnedMessages(
+  pinnedMessagesMessageIds: ReadonlyArray<string>
+) {
+  const pinnedMessagesLimit = getPinnedMessagesLimit();
+  const pinnedMessagesCount = pinnedMessagesMessageIds.length;
+  return pinnedMessagesCount >= pinnedMessagesLimit;
+}
+
 export function getLastChallengeError(
   message: Pick<MessageWithUIFieldsType, 'errors'>
 ): ShallowChallengeError | undefined {