diff --git a/.changeset/slimy-meteors-grab.md b/.changeset/slimy-meteors-grab.md
new file mode 100644
index 0000000000..a845151cc8
--- /dev/null
+++ b/.changeset/slimy-meteors-grab.md
@@ -0,0 +1,2 @@
+---
+---
diff --git a/server/src/routes/admin/domains.ts b/server/src/routes/admin/domains.ts
index 873b4390ce..bff8309da0 100644
--- a/server/src/routes/admin/domains.ts
+++ b/server/src/routes/admin/domains.ts
@@ -14,6 +14,56 @@ import { enrichOrganization } from "../../services/enrichment.js";
 const slackDb = new SlackDatabase();
 const logger = createLogger("admin-domains");
 
+/**
+ * SQL query to fetch combined activity history for a contact.
+ * Combines email activities with event registrations via UNION ALL.
+ * Parameter $1 is the contact UUID.
+ */
+const CONTACT_ACTIVITIES_QUERY = `
+  SELECT * FROM (
+    -- Email activities
+    SELECT
+      eca.id as activity_id,
+      'email' as activity_type,
+      eca.subject as title,
+      eca.direction as description,
+      eca.insights,
+      eca.metadata,
+      eca.email_date as activity_date,
+      eca.created_at,
+      eac.role,
+      eac.is_primary
+    FROM email_contact_activities eca
+    INNER JOIN email_activity_contacts eac ON eac.activity_id = eca.id
+    WHERE eac.contact_id = $1
+
+    UNION ALL
+
+    -- Event registrations
+    SELECT
+      er.id as activity_id,
+      'event_registration' as activity_type,
+      e.title as title,
+      er.registration_status as description,
+      NULL::TEXT as insights,
+      jsonb_build_object(
+        'event_id', er.event_id,
+        'event_slug', e.slug,
+        'ticket_type', er.ticket_type,
+        'attended', er.attended,
+        'registration_source', er.registration_source
+      ) as metadata,
+      er.registered_at as activity_date,
+      er.created_at,
+      'registrant' as role,
+      true as is_primary
+    FROM event_registrations er
+    INNER JOIN events e ON e.id = er.event_id
+    WHERE er.email_contact_id = $1
+  ) combined
+  ORDER BY activity_date DESC NULLS LAST
+`;
+
 interface DomainRoutesConfig {
   workos: WorkOS | null;
 }
@@ -571,26 +621,8 @@ export function setupDomainRoutes(
 
         const contact = contactResult.rows[0];
 
-        // Get activity history for this contact
-        const activitiesResult = await pool.query(
-          `SELECT
-            eca.id as activity_id,
-            eca.email_id,
-            eca.message_id,
-            eca.subject,
-            eca.direction,
-            eca.insights,
-            eca.metadata,
-            eca.email_date,
-            eca.created_at,
-            eac.role,
-            eac.is_primary
-          FROM email_contact_activities eca
-          INNER JOIN email_activity_contacts eac ON eac.activity_id = eca.id
-          WHERE eac.contact_id = $1
-          ORDER BY eca.email_date DESC`,
-          [id]
-        );
+        // Get activity history for this contact (emails + event registrations)
+        const activitiesResult = await pool.query(CONTACT_ACTIVITIES_QUERY, [id]);
 
         res.json({
           ...contact,
@@ -649,26 +681,8 @@ export function setupDomainRoutes(
 
         const contact = contactResult.rows[0];
 
-        // Get activity history for this contact
-        const activitiesResult = await pool.query(
-          `SELECT
-            eca.id as activity_id,
-            eca.email_id,
-            eca.message_id,
-            eca.subject,
-            eca.direction,
-            eca.insights,
-            eca.metadata,
-            eca.email_date,
-            eca.created_at,
-            eac.role,
-            eac.is_primary
-          FROM email_contact_activities eca
-          INNER JOIN email_activity_contacts eac ON eac.activity_id = eca.id
-          WHERE eac.contact_id = $1
-          ORDER BY eca.email_date DESC`,
-          [contact.id]
-        );
+        // Get activity history for this contact (emails + event registrations)
+        const activitiesResult = await pool.query(CONTACT_ACTIVITIES_QUERY, [contact.id]);
 
         res.json({
           ...contact,