diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index 8caedc54717e..b4001ac8c1f8 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -1160,44 +1160,96 @@
       ]]></handler>
 
       <handler event="keydown" group="system"><![CDATA[
-        if (event.altKey || event.shiftKey)
-          return;
+        let {altKey, shiftKey} = event;
+        let [accel, nonAccel] = AppConstants.platform == "macosx" ? [event.metaKey, event.ctrlKey] : [event.ctrlKey, event.metaKey];
 
-        let wrongModifiers;
-        if (AppConstants.platform == "macosx") {
-          wrongModifiers = !event.metaKey;
-        } else {
-          wrongModifiers = !event.ctrlKey || event.metaKey;
+        let keyComboForMove = accel && shiftKey && !altKey && !nonAccel;
+        let keyComboForFocus = accel && !shiftKey && !altKey && !nonAccel;
+
+        if (!keyComboForMove && !keyComboForFocus) {
+          return;
         }
 
-        if (wrongModifiers)
-          return;
-
         // Don't check if the event was already consumed because tab navigation
         // should work always for better user experience.
-
+        let {visibleTabs, selectedTab} = gBrowser;
+        let {arrowKeysShouldWrap} = this;
+        let focusedTabIndex = this.ariaFocusedIndex;
+        if (focusedTabIndex == -1) {
+          focusedTabIndex = visibleTabs.indexOf(selectedTab);
+        }
+        let lastFocusedTabIndex = focusedTabIndex;
         switch (event.keyCode) {
           case KeyEvent.DOM_VK_UP:
-            gBrowser.moveTabBackward();
+            if (keyComboForMove) {
+              gBrowser.moveTabBackward();
+            } else {
+              focusedTabIndex--;
+            }
             break;
           case KeyEvent.DOM_VK_DOWN:
-            gBrowser.moveTabForward();
+            if (keyComboForMove) {
+              gBrowser.moveTabForward();
+            } else {
+              focusedTabIndex++;
+            }
             break;
           case KeyEvent.DOM_VK_RIGHT:
           case KeyEvent.DOM_VK_LEFT:
-            gBrowser.moveTabOver(event);
+            if (keyComboForMove) {
+              gBrowser.moveTabOver(event);
+            } else {
+              let isRTL = Services.locale.isAppLocaleRTL;
+              if ((!isRTL && event.keyCode == KeyEvent.DOM_VK_RIGHT) ||
+                  (isRTL && event.keyCode == KeyEvent.DOM_VK_LEFT)) {
+                focusedTabIndex++;
+              } else {
+                focusedTabIndex--;
+              }
+            }
             break;
           case KeyEvent.DOM_VK_HOME:
-            gBrowser.moveTabToStart();
+            if (keyComboForMove) {
+              gBrowser.moveTabToStart();
+            } else {
+              focusedTabIndex = 0;
+            }
             break;
           case KeyEvent.DOM_VK_END:
-            gBrowser.moveTabToEnd();
+            if (keyComboForMove) {
+              gBrowser.moveTabToEnd();
+            } else {
+              focusedTabIndex = visibleTabs.length - 1;
+            }
+            break;
+          case KeyEvent.DOM_VK_SPACE:
+            if (visibleTabs[lastFocusedTabIndex].multiselected) {
+              gBrowser.removeFromMultiSelectedTabs(visibleTabs[lastFocusedTabIndex]);
+            } else {
+              gBrowser.addToMultiSelectedTabs(visibleTabs[lastFocusedTabIndex], false);
+            }
             break;
           default:
             // Consume the keydown event for the above keyboard
             // shortcuts only.
             return;
         }
+
+        if (arrowKeysShouldWrap) {
+          if (focusedTabIndex >= visibleTabs.length) {
+            focusedTabIndex = 0;
+          } else if (focusedTabIndex < 0) {
+            focusedTabIndex = visibleTabs.length - 1;
+          }
+        } else {
+          focusedTabIndex = Math.min(visibleTabs.length - 1, Math.max(0, focusedTabIndex));
+        }
+
+        if (keyComboForFocus &&
+            focusedTabIndex != lastFocusedTabIndex) {
+          this.ariaFocusedItem = visibleTabs[focusedTabIndex];
+        }
+
         event.preventDefault();
       ]]></handler>
 
diff --git a/browser/base/content/test/tabs/browser.ini b/browser/base/content/test/tabs/browser.ini
index a2dc9b9a7e4a..644548a9a60a 100644
--- a/browser/base/content/test/tabs/browser.ini
+++ b/browser/base/content/test/tabs/browser.ini
@@ -38,6 +38,8 @@ support-files =
 [browser_multiselect_tabs_reload.js]
 [browser_multiselect_tabs_reorder.js]
 [browser_multiselect_tabs_using_Ctrl.js]
+[browser_multiselect_tabs_using_keyboard.js]
+skip-if = os == 'mac' # Skipped because macOS keyboard support requires changing system settings
 [browser_multiselect_tabs_using_selectedTabs.js]
 [browser_multiselect_tabs_using_Shift_and_Ctrl.js]
 [browser_multiselect_tabs_using_Shift.js]
diff --git a/browser/base/content/test/tabs/browser_multiselect_tabs_using_keyboard.js b/browser/base/content/test/tabs/browser_multiselect_tabs_using_keyboard.js
new file mode 100644
index 000000000000..c5ad2f6f30af
--- /dev/null
+++ b/browser/base/content/test/tabs/browser_multiselect_tabs_using_keyboard.js
@@ -0,0 +1,101 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const PREF_MULTISELECT_TABS = "browser.tabs.multiselect";
+
+function synthesizeKeyAndWaitForFocus(element, keyCode, options) {
+  let focused = BrowserTestUtils.waitForEvent(element, "focus");
+  EventUtils.synthesizeKey(keyCode, options);
+  return focused;
+}
+
+function synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab, keyCode, options) {
+  let focused = TestUtils.waitForCondition(() => {
+    return tab.classList.contains("keyboard-focused-tab");
+  }, "Waiting for tab to get keyboard focus");
+  EventUtils.synthesizeKey(keyCode, options);
+  return focused;
+}
+
+add_task(async function setup() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_MULTISELECT_TABS, true]],
+  });
+
+  let prevActiveElement = document.activeElement;
+  registerCleanupFunction(() => {
+    prevActiveElement.focus();
+  });
+});
+
+add_task(async function changeSelectionUsingKeyboard() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_MULTISELECT_TABS, true]],
+  });
+
+  const tab1 = await addTab("http://mochi.test:8888/1");
+  const tab2 = await addTab("http://mochi.test:8888/2");
+  const tab3 = await addTab("http://mochi.test:8888/3");
+  const tab4 = await addTab("http://mochi.test:8888/4");
+  const tab5 = await addTab("http://mochi.test:8888/5");
+
+  await BrowserTestUtils.switchTab(gBrowser, tab3);
+  info("Move focus to location bar using the keyboard");
+  await synthesizeKeyAndWaitForFocus(gURLBar, "l", {accelKey: true});
+  ok(document.activeElement, "urlbar should be focused");
+
+  info("Move focus to the selected tab using the keyboard");
+  let identityBox = document.querySelector("#identity-box");
+  await synthesizeKeyAndWaitForFocus(identityBox, "VK_TAB", {shiftKey: true});
+  await synthesizeKeyAndWaitForFocus(tab3, "VK_TAB", {shiftKey: true});
+  is(document.activeElement, tab3, "Tab3 should be focused");
+
+  info("Move focus to tab 1 using the keyboard");
+  await synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab2, "KEY_ArrowLeft", {accelKey: true});
+  await synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab1, "KEY_ArrowLeft", {accelKey: true});
+  is(gBrowser.tabContainer.ariaFocusedItem, tab1, "Tab1 should be the ariaFocusedItem");
+
+  ok(!tab1.multiselected, "Tab1 shouldn't be multiselected");
+  info("Select tab1 using keyboard");
+  EventUtils.synthesizeKey("VK_SPACE", { accelKey: true });
+  ok(tab1.multiselected, "Tab1 should be multiselected");
+
+  info("Move focus to tab 5 using the keyboard");
+  await synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab2, "KEY_ArrowRight", { accelKey: true });
+  await synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab3, "KEY_ArrowRight", { accelKey: true });
+  await synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab4, "KEY_ArrowRight", { accelKey: true });
+  await synthesizeKeyAndWaitForTabToGetKeyboardFocus(tab5, "KEY_ArrowRight", { accelKey: true });
+
+  ok(!tab5.multiselected, "Tab5 shouldn't be multiselected");
+  info("Select tab5 using keyboard");
+  EventUtils.synthesizeKey("VK_SPACE", { accelKey: true });
+  ok(tab5.multiselected, "Tab5 should be multiselected");
+
+  ok(tab1.multiselected && gBrowser._multiSelectedTabsSet.has(tab1), "Tab1 is (multi) selected");
+  ok(tab3.multiselected && gBrowser._multiSelectedTabsSet.has(tab3), "Tab3 is (multi) selected");
+  ok(tab5.multiselected && gBrowser._multiSelectedTabsSet.has(tab5), "Tab5 is (multi) selected");
+  is(gBrowser.multiSelectedTabsCount, 3, "Three tabs (multi) selected");
+  is(tab3, gBrowser.selectedTab, "Tab3 is still the selected tab");
+
+  await synthesizeKeyAndWaitForFocus(tab4, "KEY_ArrowLeft", {});
+  is(tab4, gBrowser.selectedTab, "Tab4 is now selected tab since tab5 had keyboard focus");
+
+  is(tab4.previousElementSibling, tab3, "tab4 should be after tab3");
+  is(tab4.nextElementSibling, tab5, "tab4 should be before tab5");
+
+  let tabsReordered = BrowserTestUtils.waitForCondition(() => {
+    return tab4.previousElementSibling == tab2 &&
+           tab4.nextElementSibling == tab3;
+  }, "tab4 should now be after tab2 and before tab3");
+  EventUtils.synthesizeKey("KEY_ArrowLeft", {accelKey: true, shiftKey: true});
+  await tabsReordered;
+
+  is(tab4.previousElementSibling, tab2, "tab4 should be after tab2");
+  is(tab4.nextElementSibling, tab3, "tab4 should be before tab3");
+
+  BrowserTestUtils.removeTab(tab1);
+  BrowserTestUtils.removeTab(tab2);
+  BrowserTestUtils.removeTab(tab3);
+  BrowserTestUtils.removeTab(tab4);
+  BrowserTestUtils.removeTab(tab5);
+});
diff --git a/browser/themes/linux/browser.css b/browser/themes/linux/browser.css
index a8378defaa07..e75336ad00e6 100644
--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -498,7 +498,8 @@ notification[value="translation"] menulist > .menulist-dropmarker {
   }
 }
 
-.tabbrowser-tab:focus > .tab-stack > .tab-content {
+.keyboard-focused-tab > .tab-stack > .tab-content,
+.tabbrowser-tab:focus:not([aria-activedescendant]) > .tab-stack > .tab-content {
   outline: 1px dotted;
   outline-offset: -6px;
 }
diff --git a/browser/themes/osx/browser.css b/browser/themes/osx/browser.css
index c37d65a35f6d..fce9fe74ba3b 100644
--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -669,9 +669,9 @@ html|input.urlbar-input {
   text-shadow: inherit;
 }
 
-.tabbrowser-tab:focus > .tab-stack > .tab-content > .tab-label-container:not([pinned]),
-.tabbrowser-tab:focus > .tab-stack > .tab-content > .tab-icon-image[pinned],
-.tabbrowser-tab:focus > .tab-stack > .tab-content > .tab-throbber[pinned] {
+:-moz-any(.keyboard-focused-tab, .tabbrowser-tab:focus:not([aria-activedescendant])) > .tab-stack > .tab-content > .tab-label-container:not([pinned]),
+:-moz-any(.keyboard-focused-tab, .tabbrowser-tab:focus:not([aria-activedescendant])) > .tab-stack > .tab-content > .tab-icon-image[pinned],
+:-moz-any(.keyboard-focused-tab, .tabbrowser-tab:focus:not([aria-activedescendant])) > .tab-stack > .tab-content > .tab-throbber[pinned] {
   box-shadow: var(--focus-ring-box-shadow);
 }
 
diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index 81accc94252c..f0f58f78f29e 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -691,7 +691,8 @@ html|*.urlbar-input:-moz-lwtheme::placeholder,
 }
 
 /* tabbrowser-tab focus ring */
-.tabbrowser-tab:focus > .tab-stack > .tab-content {
+.keyboard-focused-tab > .tab-stack > .tab-content,
+.tabbrowser-tab:focus:not([aria-activedescendant]) > .tab-stack > .tab-content {
   outline: 1px dotted;
   outline-offset: -6px;
 }
diff --git a/toolkit/content/widgets/tabbox.xml b/toolkit/content/widgets/tabbox.xml
index 5418f9343d00..15e6678a8294 100644
--- a/toolkit/content/widgets/tabbox.xml
+++ b/toolkit/content/widgets/tabbox.xml
@@ -199,6 +199,53 @@
         </setter>
       </property>
 
+      <field name="ACTIVE_DESCENDANT_ID" readonly="true"><![CDATA[
+        "keyboard-focused-tab-" + Math.trunc(Math.random() * 1000000);
+      ]]></field>
+
+      <property name="ariaFocusedIndex" readonly="true">
+        <getter>
+        <![CDATA[
+          const tabs = this.children;
+          for (var i = 0; i < tabs.length; i++) {
+            if (tabs[i].id == this.ACTIVE_DESCENDANT_ID)
+              return i;
+          }
+          return -1;
+        ]]>
+        </getter>
+      </property>
+
+      <property name="ariaFocusedItem">
+        <getter>
+        <![CDATA[
+          return document.getElementById(this.ACTIVE_DESCENDANT_ID);
+        ]]>
+        </getter>
+
+        <setter>
+        <![CDATA[
+          let setNewItem = val && this.getIndexOfItem(val) != -1;
+          let clearExistingItem = this.ariaFocusedItem && (!val || setNewItem);
+          if (clearExistingItem) {
+            let ariaFocusedItem = this.ariaFocusedItem;
+            ariaFocusedItem.classList.remove("keyboard-focused-tab");
+            ariaFocusedItem.id = "";
+            this.selectedItem.removeAttribute("aria-activedescendant");
+          }
+
+          if (setNewItem) {
+            this.ariaFocusedItem = null;
+            val.id = this.ACTIVE_DESCENDANT_ID;
+            val.classList.add("keyboard-focused-tab");
+            this.selectedItem.setAttribute("aria-activedescendant", this.ACTIVE_DESCENDANT_ID);
+          }
+
+          return val;
+        ]]>
+        </setter>
+      </property>
+
       <method name="getIndexOfItem">
         <parameter name="item"/>
         <body>
@@ -223,6 +270,8 @@
         <parameter name="aWrap"/>
         <body>
         <![CDATA[
+          this.ariaFocusedItem = null;
+
           var requestedTab = aNewTab;
           while (aNewTab.hidden || aNewTab.disabled || !this._canAdvanceToTab(aNewTab)) {
             aNewTab = aFallbackDir == -1 ? aNewTab.previousElementSibling : aNewTab.nextElementSibling;
@@ -277,7 +326,7 @@
         <parameter name="aWrap"/>
         <body>
         <![CDATA[
-          var startTab = this.selectedItem;
+          var startTab = this.ariaFocusedItem || this.selectedItem;
           var next = startTab[(aDir == -1 ? "previous" : "next") + "ElementSibling"];
           if (!next && aWrap) {
             next = aDir == -1 ? this.children[this.children.length - 1] :
@@ -504,6 +553,8 @@
         if (this.disabled)
           return;
 
+        this.parentNode.ariaFocusedItem = null;
+
         if (this != this.parentNode.selectedItem) { // Not selected yet
           let stopwatchid = this.parentNode.getAttribute("stopwatchid");
           if (stopwatchid) {