diff --git a/prefs/compact-mode.yaml b/prefs/compact-mode.yaml
index 2470ffcd68..d39eea82c0 100644
--- a/prefs/compact-mode.yaml
+++ b/prefs/compact-mode.yaml
@@ -32,6 +32,9 @@
 - name: zen.view.compact.show-background-tab-toast
   value: true
 
+- name: zen.view.compact.enable-on-fullscreen
+  value: true
+
 # Do not edit manually
 - name: zen.view.compact.should-enable-at-startup
   hidden: true
diff --git a/src/zen/compact-mode/ZenCompactMode.mjs b/src/zen/compact-mode/ZenCompactMode.mjs
index 87d48e0154..7c255f0e48 100644
--- a/src/zen/compact-mode/ZenCompactMode.mjs
+++ b/src/zen/compact-mode/ZenCompactMode.mjs
@@ -57,10 +57,18 @@ var gZenCompactModeManager = {
     const tabIsRightObserver = this._updateSidebarIsOnRight.bind(this);
     Services.prefs.addObserver('zen.tabs.vertical.right-side', tabIsRightObserver);
 
+    const enableOnFullscreenObserver = this._updateEnableOnFullscreen.bind(this);
+    Services.prefs.addObserver('zen.view.compact.enable-on-fullscreen', enableOnFullscreenObserver);
+    window.addEventListener('sizemodechange', this.enableOnFullscreen.bind(this));
+
     window.addEventListener(
       'unload',
       () => {
         Services.prefs.removeObserver('zen.tabs.vertical.right-side', tabIsRightObserver);
+        Services.prefs.removeObserver(
+          'zen.view.compact.enable-on-fullscreen',
+          enableOnFullscreenObserver
+        );
       },
       { once: true }
     );
@@ -95,11 +103,19 @@ var gZenCompactModeManager = {
     });
   },
 
+  get fullscreen() {
+    return window.windowState === window.STATE_FULLSCREEN;
+  },
+
   get preference() {
     return lazyCompactMode.mainAppWrapper.getAttribute('zen-compact-mode') === 'true';
   },
 
   get shouldBeCompact() {
+    if (this._enableOnFullscreen && this.fullscreen) {
+      return true;
+    }
+
     return !document.documentElement.getAttribute('chromehidden').includes('toolbar');
   },
 
@@ -142,6 +158,19 @@ var gZenCompactModeManager = {
     return gNavToolbox;
   },
 
+  enableOnFullscreen() {
+    if (!this._enableOnFullscreen) {
+      return;
+    }
+
+    if (this.fullscreen) {
+      this._oldPreference = this.preference;
+      this.preference = true;
+    } else {
+      this.preference = this._oldPreference;
+    }
+  },
+
   addHasPolyfillObserver() {
     this.sidebarObserverId = ZenHasPolyfill.observeSelectorExistence(
       this.sidebar,
@@ -450,6 +479,10 @@ var gZenCompactModeManager = {
     this._sidebarIsOnRight = Services.prefs.getBoolPref('zen.tabs.vertical.right-side');
   },
 
+  _updateEnableOnFullscreen() {
+    this._enableOnFullscreen = Services.prefs.getBoolPref('zen.view.compact.enable-on-fullscreen');
+  },
+
   toggleSidebar() {
     this.sidebar.toggleAttribute('zen-user-show');
   },