diff --git a/changelog.d/5623.feature b/changelog.d/5623.feature
new file mode 100644
index 0000000000..b73080e88d
--- /dev/null
+++ b/changelog.d/5623.feature
@@ -0,0 +1 @@
+Add default push rule to ignore reactions.
diff --git a/synapse/push/baserules.py b/synapse/push/baserules.py
index 96d087de22..134bf805eb 100644
--- a/synapse/push/baserules.py
+++ b/synapse/push/baserules.py
@@ -1,5 +1,6 @@
 # Copyright 2015, 2016 OpenMarket Ltd
 # Copyright 2017 New Vector Ltd
+# Copyright 2019 The Matrix.org Foundation C.I.C.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -248,6 +249,18 @@ BASE_APPEND_OVERRIDE_RULES = [
         ],
         "actions": ["notify", {"set_tweak": "highlight", "value": True}],
     },
+    {
+        "rule_id": "global/override/.m.rule.reaction",
+        "conditions": [
+            {
+                "kind": "event_match",
+                "key": "type",
+                "pattern": "m.reaction",
+                "_id": "_reaction",
+            }
+        ],
+        "actions": ["dont_notify"],
+    },
 ]