diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index e2ecda3..63ce7eb 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -1143,3 +1143,13 @@
        purpose: PURPOSE_BUGFIX
    }
 }
+
+flag {
+  namespace: "systemui"
+  name: "qs_register_setting_observer_on_bg_thread"
+  description: "Registers Quick Settings content providers on background thread"
+  bug: "351766769"
+  metadata {
+    purpose: PURPOSE_BUGFIX
+  }
+}
diff --git a/packages/SystemUI/multivalentTests/src/com/android/systemui/qs/SettingObserverTest.kt b/packages/SystemUI/multivalentTests/src/com/android/systemui/qs/SettingObserverTest.kt
new file mode 100644
index 0000000..188f2ac
--- /dev/null
+++ b/packages/SystemUI/multivalentTests/src/com/android/systemui/qs/SettingObserverTest.kt
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.systemui.qs
+
+import android.net.Uri
+import android.os.Handler
+import android.os.Looper
+import android.platform.test.annotations.DisableFlags
+import android.platform.test.annotations.EnableFlags
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import com.android.systemui.Flags
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.util.settings.SettingsProxy
+import com.google.common.truth.Truth.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.Captor
+import org.mockito.Mock
+import org.mockito.MockitoAnnotations
+import org.mockito.kotlin.any
+import org.mockito.kotlin.capture
+import org.mockito.kotlin.eq
+import org.mockito.kotlin.reset
+import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
+
+@SmallTest
+@RunWith(AndroidJUnit4::class)
+class SettingObserverTest : SysuiTestCase() {
+
+    private val DEFAULT_VALUE = 7
+
+    @Mock lateinit var settingsProxy: SettingsProxy
+    @Captor private lateinit var argumentCaptor: ArgumentCaptor<Runnable>
+
+    private lateinit var testSettingObserver: SettingObserver
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+        whenever(settingsProxy.getInt(any(), any())).thenReturn(5)
+        whenever(settingsProxy.getUriFor(any())).thenReturn(Uri.parse("content://test_uri"))
+        testSettingObserver =
+            object :
+                SettingObserver(
+                    settingsProxy,
+                    Handler(Looper.getMainLooper()),
+                    "test_setting",
+                    DEFAULT_VALUE
+                ) {
+                override fun handleValueChanged(value: Int, observedChange: Boolean) {}
+            }
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_QS_REGISTER_SETTING_OBSERVER_ON_BG_THREAD)
+    fun setListening_true_settingsProxyRegistered() {
+        testSettingObserver.isListening = true
+        verify(settingsProxy)
+            .registerContentObserverAsync(
+                any<Uri>(),
+                eq(false),
+                eq(testSettingObserver),
+                capture(argumentCaptor)
+            )
+        assertThat(testSettingObserver.value).isEqualTo(5)
+
+        // Verify if the callback applies updated value after the fact
+        whenever(settingsProxy.getInt(any(), any())).thenReturn(12341234)
+        argumentCaptor.value.run()
+        assertThat(testSettingObserver.value).isEqualTo(12341234)
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_QS_REGISTER_SETTING_OBSERVER_ON_BG_THREAD)
+    fun setListening_false_settingsProxyRegistered() {
+        testSettingObserver.isListening = true
+        reset(settingsProxy)
+        testSettingObserver.isListening = false
+
+        verify(settingsProxy).unregisterContentObserverAsync(eq(testSettingObserver))
+    }
+
+    @Test
+    @DisableFlags(Flags.FLAG_QS_REGISTER_SETTING_OBSERVER_ON_BG_THREAD)
+    fun setListening_bgFlagDisabled_true_settingsProxyRegistered() {
+        testSettingObserver.isListening = true
+        verify(settingsProxy)
+            .registerContentObserverSync(any<Uri>(), eq(false), eq(testSettingObserver))
+    }
+
+    @Test
+    @DisableFlags(Flags.FLAG_QS_REGISTER_SETTING_OBSERVER_ON_BG_THREAD)
+    fun setListening_bgFlagDisabled_false_settingsProxyRegistered() {
+        testSettingObserver.isListening = true
+        reset(settingsProxy)
+        testSettingObserver.isListening = false
+
+        verify(settingsProxy).unregisterContentObserverSync(eq(testSettingObserver))
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/qs/SettingObserver.java b/packages/SystemUI/src/com/android/systemui/qs/SettingObserver.java
index 6092348..2287f4d 100644
--- a/packages/SystemUI/src/com/android/systemui/qs/SettingObserver.java
+++ b/packages/SystemUI/src/com/android/systemui/qs/SettingObserver.java
@@ -19,6 +19,7 @@
 import android.database.ContentObserver;
 import android.os.Handler;
 
+import com.android.systemui.Flags;
 import com.android.systemui.statusbar.policy.Listenable;
 import com.android.systemui.util.settings.SecureSettings;
 import com.android.systemui.util.settings.SettingsProxy;
@@ -74,10 +75,20 @@
         mListening = listening;
         if (listening) {
             mObservedValue = getValueFromProvider();
-            mSettingsProxy.registerContentObserverSync(
-                    mSettingsProxy.getUriFor(mSettingName), false, this);
+            if (Flags.qsRegisterSettingObserverOnBgThread()) {
+                mSettingsProxy.registerContentObserverAsync(
+                        mSettingsProxy.getUriFor(mSettingName), false, this,
+                        () -> mObservedValue = getValueFromProvider());
+            } else {
+                mSettingsProxy.registerContentObserverSync(
+                        mSettingsProxy.getUriFor(mSettingName), false, this);
+            }
         } else {
-            mSettingsProxy.unregisterContentObserverSync(this);
+            if (Flags.qsRegisterSettingObserverOnBgThread()) {
+                mSettingsProxy.unregisterContentObserverAsync(this);
+            } else {
+                mSettingsProxy.unregisterContentObserverSync(this);
+            }
             mObservedValue = mDefaultValue;
         }
     }