diff --git a/changelog.d/19954.feature b/changelog.d/19954.feature
new file mode 100644
index 00000000000..7a87e557663
--- /dev/null
+++ b/changelog.d/19954.feature
@@ -0,0 +1 @@
+Add experimental support for [MSC4505](https://github.com/matrix-org/matrix-spec-proposals/pull/4505): push rules for live location sharing.
diff --git a/rust/benches/evaluator.rs b/rust/benches/evaluator.rs
index 96169fd45d9..e59a6d2f6ab 100644
--- a/rust/benches/evaluator.rs
+++ b/rust/benches/evaluator.rs
@@ -215,6 +215,7 @@ fn bench_eval_message(b: &mut Bencher) {
         false,
         false,
         false,
+        false,
     );
 
     b.iter(|| eval.run(&rules, Some("bob"), Some("person"), None));
diff --git a/rust/src/push/base_rules.rs b/rust/src/push/base_rules.rs
index 47d5289006b..c71e57b0be9 100644
--- a/rust/src/push/base_rules.rs
+++ b/rust/src/push/base_rules.rs
@@ -273,6 +273,22 @@ pub const BASE_APPEND_OVERRIDE_RULES: &[PushRule] = &[
         default: true,
         default_enabled: true,
     },
+    // MSC4505: explicitly suppress live location share beacon updates in unencrypted
+    // rooms (in encrypted rooms they arrive as m.room.encrypted and can only be
+    // suppressed client-side after decryption).
+    PushRule {
+        rule_id: Cow::Borrowed("global/override/.org.matrix.msc4505.rule.beacon"),
+        priority_class: 5,
+        conditions: Cow::Borrowed(&[Condition::Known(KnownCondition::EventMatch(
+            EventMatchCondition {
+                key: Cow::Borrowed("type"),
+                pattern: Cow::Borrowed("org.matrix.msc3672.beacon"),
+            },
+        ))]),
+        actions: Cow::Borrowed(&[]),
+        default: true,
+        default_enabled: true,
+    },
 ];
 
 pub const BASE_APPEND_CONTENT_RULES: &[PushRule] = &[PushRule {
@@ -721,6 +737,43 @@ pub const BASE_APPEND_UNDERRIDE_RULES: &[PushRule] = &[
         default: true,
         default_enabled: true,
     },
+    PushRule {
+        rule_id: Cow::Borrowed("global/underride/.org.matrix.msc4505.rule.beacon_info_one_to_one"),
+        priority_class: 1,
+        conditions: Cow::Borrowed(&[
+            Condition::Known(KnownCondition::RoomMemberCount {
+                is: Some(Cow::Borrowed("2")),
+            }),
+            Condition::Known(KnownCondition::EventMatch(EventMatchCondition {
+                key: Cow::Borrowed("type"),
+                pattern: Cow::Borrowed("org.matrix.msc3672.beacon_info"),
+            })),
+            Condition::Known(KnownCondition::EventPropertyIs(EventPropertyIsCondition {
+                key: Cow::Borrowed("content.live"),
+                value: Cow::Owned(SimpleJsonValue::Bool(true)),
+            })),
+        ]),
+        actions: Cow::Borrowed(&[Action::Notify, SOUND_ACTION]),
+        default: true,
+        default_enabled: true,
+    },
+    PushRule {
+        rule_id: Cow::Borrowed("global/underride/.org.matrix.msc4505.rule.beacon_info"),
+        priority_class: 1,
+        conditions: Cow::Borrowed(&[
+            Condition::Known(KnownCondition::EventMatch(EventMatchCondition {
+                key: Cow::Borrowed("type"),
+                pattern: Cow::Borrowed("org.matrix.msc3672.beacon_info"),
+            })),
+            Condition::Known(KnownCondition::EventPropertyIs(EventPropertyIsCondition {
+                key: Cow::Borrowed("content.live"),
+                value: Cow::Owned(SimpleJsonValue::Bool(true)),
+            })),
+        ]),
+        actions: Cow::Borrowed(&[Action::Notify]),
+        default: true,
+        default_enabled: true,
+    },
 ];
 
 lazy_static! {
diff --git a/rust/src/push/evaluator.rs b/rust/src/push/evaluator.rs
index 1cbca4c6355..250d2890c09 100644
--- a/rust/src/push/evaluator.rs
+++ b/rust/src/push/evaluator.rs
@@ -637,6 +637,7 @@ fn test_requires_room_version_supports_condition() {
             false,
             false,
             false,
+            false,
         ),
         None,
         None,
diff --git a/rust/src/push/mod.rs b/rust/src/push/mod.rs
index 780d7a8cbd8..2854dd6e889 100644
--- a/rust/src/push/mod.rs
+++ b/rust/src/push/mod.rs
@@ -559,6 +559,7 @@ pub struct FilteredPushRules {
     msc4028_push_encrypted_events: bool,
     msc4210_enabled: bool,
     msc4306_enabled: bool,
+    msc4505_enabled: bool,
 }
 
 #[pymethods]
@@ -574,6 +575,7 @@ impl FilteredPushRules {
         msc4028_push_encrypted_events: bool,
         msc4210_enabled: bool,
         msc4306_enabled: bool,
+        msc4505_enabled: bool,
     ) -> Self {
         Self {
             push_rules,
@@ -584,6 +586,7 @@ impl FilteredPushRules {
             msc4028_push_encrypted_events,
             msc4210_enabled,
             msc4306_enabled,
+            msc4505_enabled,
         }
     }
 
@@ -620,6 +623,12 @@ impl FilteredPushRules {
                     return false;
                 }
 
+                if !self.msc4505_enabled
+                    && rule.rule_id.contains("/.org.matrix.msc4505.rule.beacon")
+                {
+                    return false;
+                }
+
                 if !self.msc4028_push_encrypted_events
                     && rule.rule_id == "global/override/.org.matrix.msc4028.encrypted_event"
                 {
diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index f99f7b139ec..c1c83100676 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -156,6 +156,12 @@ def read_config(
             "msc3381_polls_enabled", False
         )
 
+        # MSC4505: default push rules for live location sharing — notify on
+        # beacon_info start events (the MSC3672 state event), suppress beacon
+        # updates. Unstable rule ids: .org.matrix.msc4505.rule.beacon_info
+        # (_one_to_one) / .org.matrix.msc4505.rule.beacon.
+        self.msc4505_enabled: bool = experimental.get("msc4505_enabled", False)
+
         # MSC3912: Relation-based redactions.
         self.msc3912_enabled: bool = experimental.get("msc3912_enabled", False)
 
diff --git a/synapse/storage/databases/main/push_rule.py b/synapse/storage/databases/main/push_rule.py
index d361166cec4..6aa1baa5a64 100644
--- a/synapse/storage/databases/main/push_rule.py
+++ b/synapse/storage/databases/main/push_rule.py
@@ -107,6 +107,7 @@ def _load_rules(
         msc4028_push_encrypted_events=experimental_config.msc4028_push_encrypted_events,
         msc4210_enabled=experimental_config.msc4210_enabled,
         msc4306_enabled=experimental_config.msc4306_enabled,
+        msc4505_enabled=experimental_config.msc4505_enabled,
     )
 
     return filtered_rules
diff --git a/synapse/synapse_rust/push.pyi b/synapse/synapse_rust/push.pyi
index ef0d5f94f4f..8799d08a151 100644
--- a/synapse/synapse_rust/push.pyi
+++ b/synapse/synapse_rust/push.pyi
@@ -50,6 +50,7 @@ class FilteredPushRules:
         msc4028_push_encrypted_events: bool,
         msc4210_enabled: bool,
         msc4306_enabled: bool,
+        msc4505_enabled: bool,
     ): ...
     def rules(self) -> Collection[tuple[PushRule, bool]]: ...