diff --git a/assets/reader.css b/assets/reader.css
index 0a67157..435e8ff 100644
--- a/assets/reader.css
+++ b/assets/reader.css
@@ -4,6 +4,54 @@
  * Uses Indiekit CSS custom properties for automatic dark mode support
  */
 
+/* ==========================================================================
+   Fediverse Lookup
+   ========================================================================== */
+
+.ap-lookup {
+  display: flex;
+  gap: var(--space-xs);
+  margin-bottom: var(--space-m);
+}
+
+.ap-lookup__input {
+  flex: 1;
+  padding: var(--space-s) var(--space-m);
+  border: var(--border-width-thin) solid var(--color-outline);
+  border-radius: var(--border-radius-small);
+  background: var(--color-offset);
+  color: var(--color-on-background);
+  font-size: var(--font-size-m);
+  font-family: inherit;
+}
+
+.ap-lookup__input::placeholder {
+  color: var(--color-on-offset);
+}
+
+.ap-lookup__input:focus {
+  outline: 2px solid var(--color-primary);
+  outline-offset: -1px;
+  border-color: var(--color-primary);
+}
+
+.ap-lookup__btn {
+  padding: var(--space-s) var(--space-m);
+  border: var(--border-width-thin) solid var(--color-primary);
+  border-radius: var(--border-radius-small);
+  background: var(--color-primary);
+  color: var(--color-on-primary);
+  font-size: var(--font-size-m);
+  font-family: inherit;
+  font-weight: 600;
+  cursor: pointer;
+  white-space: nowrap;
+}
+
+.ap-lookup__btn:hover {
+  opacity: 0.9;
+}
+
 /* ==========================================================================
    Tab Navigation
    ========================================================================== */
diff --git a/index.js b/index.js
index 7227baa..3878a88 100644
--- a/index.js
+++ b/index.js
@@ -57,6 +57,7 @@ import {
   featuredTagsAddController,
   featuredTagsRemoveController,
 } from "./lib/controllers/featured-tags.js";
+import { resolveController } from "./lib/controllers/resolve.js";
 import {
   refollowPauseController,
   refollowResumeController,
@@ -202,6 +203,7 @@ export default class ActivityPubEndpoint {
     router.post("/admin/reader/unlike", unlikeController(mp, this));
     router.post("/admin/reader/boost", boostController(mp, this));
     router.post("/admin/reader/unboost", unboostController(mp, this));
+    router.get("/admin/reader/resolve", resolveController(mp, this));
     router.get("/admin/reader/profile", remoteProfileController(mp, this));
     router.get("/admin/reader/post", postDetailController(mp, this));
     router.post("/admin/reader/follow", followController(mp, this));
diff --git a/lib/controllers/resolve.js b/lib/controllers/resolve.js
new file mode 100644
index 0000000..8702ef7
--- /dev/null
+++ b/lib/controllers/resolve.js
@@ -0,0 +1,109 @@
+/**
+ * Resolve controller — accepts any fediverse URL or handle, resolves it
+ * via lookupObject(), and redirects to the appropriate internal view.
+ */
+import {
+  Article,
+  Note,
+  Person,
+  Service,
+  Application,
+  Organization,
+  Group,
+} from "@fedify/fedify";
+
+/**
+ * GET /admin/reader/resolve?q=<url-or-handle>
+ * Resolves a fediverse URL or @user@domain handle and redirects to
+ * the post detail or remote profile view.
+ */
+export function resolveController(mountPath, plugin) {
+  return async (request, response, next) => {
+    try {
+      const query = (request.query.q || "").trim();
+
+      if (!query) {
+        return response.redirect(`${mountPath}/admin/reader`);
+      }
+
+      if (!plugin._federation) {
+        return response.status(503).render("error", {
+          title: "Error",
+          content: "Federation not initialized",
+        });
+      }
+
+      const handle = plugin.options.actor.handle;
+      const ctx = plugin._federation.createContext(
+        new URL(plugin._publicationUrl),
+        { handle, publicationUrl: plugin._publicationUrl },
+      );
+
+      const documentLoader = await ctx.getDocumentLoader({
+        identifier: handle,
+      });
+
+      // Determine if input is a URL or a handle
+      // lookupObject accepts: URLs, @user@domain, user@domain, acct:user@domain
+      let lookupInput;
+
+      try {
+        // If it parses as a URL, pass as URL object
+        const parsed = new URL(query);
+        lookupInput = parsed;
+      } catch {
+        // Not a URL — treat as handle (strip leading @ if present)
+        lookupInput = query;
+      }
+
+      let object;
+
+      try {
+        object = await ctx.lookupObject(lookupInput, { documentLoader });
+      } catch (error) {
+        console.warn(
+          `[resolve] lookupObject failed for "${query}":`,
+          error.message,
+        );
+      }
+
+      if (!object) {
+        return response.status(404).render("error", {
+          title: response.locals.__("activitypub.reader.resolve.notFoundTitle"),
+          content: response.locals.__(
+            "activitypub.reader.resolve.notFound",
+          ),
+        });
+      }
+
+      // Determine object type and redirect accordingly
+      const objectUrl =
+        object.id?.href || object.url?.href || query;
+
+      if (
+        object instanceof Person ||
+        object instanceof Service ||
+        object instanceof Application ||
+        object instanceof Organization ||
+        object instanceof Group
+      ) {
+        return response.redirect(
+          `${mountPath}/admin/reader/profile?url=${encodeURIComponent(objectUrl)}`,
+        );
+      }
+
+      if (object instanceof Note || object instanceof Article) {
+        return response.redirect(
+          `${mountPath}/admin/reader/post?url=${encodeURIComponent(objectUrl)}`,
+        );
+      }
+
+      // Unknown type — try post detail as fallback
+      return response.redirect(
+        `${mountPath}/admin/reader/post?url=${encodeURIComponent(objectUrl)}`,
+      );
+    } catch (error) {
+      next(error);
+    }
+  };
+}
diff --git a/locales/en.json b/locales/en.json
index 6d3fede..d3307ec 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -191,6 +191,13 @@
         "loadingThread": "Loading thread...",
         "threadError": "Could not load full thread"
       },
+      "resolve": {
+        "placeholder": "Paste a fediverse URL or @user@domain handle…",
+        "label": "Look up a fediverse post or account",
+        "button": "Look up",
+        "notFoundTitle": "Not found",
+        "notFound": "Could not find this post or account. The URL may be invalid, the server may be unavailable, or the content may have been deleted."
+      },
       "linkPreview": {
         "label": "Link preview"
       }
diff --git a/views/activitypub-reader.njk b/views/activitypub-reader.njk
index bd56d7c..1bdbcd0 100644
--- a/views/activitypub-reader.njk
+++ b/views/activitypub-reader.njk
@@ -4,7 +4,13 @@
 {% from "prose/macro.njk" import prose with context %}
 
 {% block readercontent %}
-  {{ heading({ text: __("activitypub.reader.title"), level: 1 }) }}
+  {# Fediverse lookup #}
+  <form action="{{ mountPath }}/admin/reader/resolve" method="get" class="ap-lookup">
+    <input type="text" name="q" class="ap-lookup__input"
+      placeholder="{{ __('activitypub.reader.resolve.placeholder') }}"
+      aria-label="{{ __('activitypub.reader.resolve.label') }}">
+    <button type="submit" class="ap-lookup__btn">{{ __("activitypub.reader.resolve.button") }}</button>
+  </form>
 
   {# Tab navigation #}
   <nav class="ap-tabs" role="tablist">