diff --git a/index.js b/index.js
index a69503a..068126b 100644
--- a/index.js
+++ b/index.js
@@ -96,6 +96,7 @@ export default class MicrosubEndpoint {
     readerRouter.get("/search", readerController.searchPage);
     readerRouter.post("/search", readerController.searchFeeds);
     readerRouter.post("/subscribe", readerController.subscribe);
+    readerRouter.post("/api/mark-read", readerController.markAllRead);
     router.use("/reader", readerRouter);
 
     return router;
diff --git a/lib/controllers/reader.js b/lib/controllers/reader.js
index 608165f..b9dae27 100644
--- a/lib/controllers/reader.js
+++ b/lib/controllers/reader.js
@@ -17,7 +17,11 @@ import {
   createFeed,
   deleteFeed,
 } from "../storage/feeds.js";
-import { getTimelineItems, getItemById } from "../storage/items.js";
+import {
+  getTimelineItems,
+  getItemById,
+  markItemsRead,
+} from "../storage/items.js";
 import { getUserId } from "../utils/auth.js";
 import {
   validateChannelName,
@@ -622,6 +626,33 @@ export async function subscribe(request, response) {
   response.redirect(`${request.baseUrl}/channels/${channelUid}/feeds`);
 }
 
+/**
+ * Mark all items in channel as read
+ * @param {object} request - Express request
+ * @param {object} response - Express response
+ * @returns {Promise<void>}
+ */
+export async function markAllRead(request, response) {
+  const { application } = request.app.locals;
+  const userId = getUserId(request);
+  const { channel: channelUid } = request.body;
+
+  const channelDocument = await getChannel(application, channelUid, userId);
+  if (!channelDocument) {
+    return response.status(404).render("404");
+  }
+
+  // Mark all items as read using the special "last-read-entry" value
+  await markItemsRead(
+    application,
+    channelDocument._id,
+    ["last-read-entry"],
+    userId,
+  );
+
+  response.redirect(`${request.baseUrl}/channels/${channelUid}`);
+}
+
 export const readerController = {
   index,
   channels,
@@ -630,6 +661,7 @@ export const readerController = {
   channel,
   settings,
   updateSettings,
+  markAllRead,
   deleteChannel: deleteChannelAction,
   feeds,
   addFeed,
diff --git a/package.json b/package.json
index 46aa30c..018d1c6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@rmdes/indiekit-endpoint-microsub",
-  "version": "1.0.15",
+  "version": "1.0.16",
   "description": "Microsub endpoint for Indiekit. Enables subscribing to feeds and reading content using the Microsub protocol.",
   "keywords": [
     "indiekit",