diff --git a/res/css/components/views/settings/devices/_FilteredDeviceList.pcss b/res/css/components/views/settings/devices/_FilteredDeviceList.pcss
index a871b08049..d60c9628fb 100644
--- a/res/css/components/views/settings/devices/_FilteredDeviceList.pcss
+++ b/res/css/components/views/settings/devices/_FilteredDeviceList.pcss
@@ -25,7 +25,7 @@ limitations under the License.
     display: grid;
     grid-gap: $spacing-16;
     margin: 0;
-    padding: 0 $spacing-8;
+    padding: 0 $spacing-16;
 }
 
 .mx_FilteredDeviceList_listItem {
diff --git a/src/components/views/settings/devices/FilteredDeviceList.tsx b/src/components/views/settings/devices/FilteredDeviceList.tsx
index 6d6668a854..4cf7ac1a63 100644
--- a/src/components/views/settings/devices/FilteredDeviceList.tsx
+++ b/src/components/views/settings/devices/FilteredDeviceList.tsx
@@ -266,8 +266,21 @@ export const FilteredDeviceList =
             onFilterChange(filterId === ALL_FILTER_ID ? undefined : filterId as DeviceSecurityVariation);
         };
 
+        const isAllSelected = selectedDeviceIds.length >= sortedDevices.length;
+        const toggleSelectAll = () => {
+            if (isAllSelected) {
+                setSelectedDeviceIds([]);
+            } else {
+                setSelectedDeviceIds(sortedDevices.map(device => device.device_id));
+            }
+        };
+
         return <div className='mx_FilteredDeviceList' ref={ref}>
-            <FilteredDeviceListHeader selectedDeviceCount={selectedDeviceIds.length}>
+            <FilteredDeviceListHeader
+                selectedDeviceCount={selectedDeviceIds.length}
+                isAllSelected={isAllSelected}
+                toggleSelectAll={toggleSelectAll}
+            >
                 { selectedDeviceIds.length
                     ? <>
                         <AccessibleButton
diff --git a/src/components/views/settings/devices/FilteredDeviceListHeader.tsx b/src/components/views/settings/devices/FilteredDeviceListHeader.tsx
index 6ecee4c8d2..561431d12e 100644
--- a/src/components/views/settings/devices/FilteredDeviceListHeader.tsx
+++ b/src/components/views/settings/devices/FilteredDeviceListHeader.tsx
@@ -17,18 +17,39 @@ limitations under the License.
 import React, { HTMLProps } from 'react';
 
 import { _t } from '../../../../languageHandler';
+import StyledCheckbox, { CheckboxStyle } from '../../elements/StyledCheckbox';
+import { Alignment } from '../../elements/Tooltip';
+import TooltipTarget from '../../elements/TooltipTarget';
 
 interface Props extends Omit<HTMLProps<HTMLDivElement>, 'className'> {
     selectedDeviceCount: number;
+    isAllSelected: boolean;
+    toggleSelectAll: () => void;
     children?: React.ReactNode;
 }
 
 const FilteredDeviceListHeader: React.FC<Props> = ({
     selectedDeviceCount,
+    isAllSelected,
+    toggleSelectAll,
     children,
     ...rest
 }) => {
+    const checkboxLabel = isAllSelected ? _t('Deselect all') : _t('Select all');
     return <div className='mx_FilteredDeviceListHeader' {...rest}>
+        <TooltipTarget
+            label={checkboxLabel}
+            alignment={Alignment.Top}
+        >
+            <StyledCheckbox
+                kind={CheckboxStyle.Solid}
+                checked={isAllSelected}
+                onChange={toggleSelectAll}
+                id='device-select-all-checkbox'
+                data-testid='device-select-all-checkbox'
+                aria-label={checkboxLabel}
+            />
+        </TooltipTarget>
         <span className='mx_FilteredDeviceListHeader_label'>
             { selectedDeviceCount > 0
                 ? _t('%(selectedDeviceCount)s sessions selected', { selectedDeviceCount })
diff --git a/test/components/views/settings/devices/FilteredDeviceListHeader-test.tsx b/test/components/views/settings/devices/FilteredDeviceListHeader-test.tsx
index 8f7ecdc924..49e8d9a861 100644
--- a/test/components/views/settings/devices/FilteredDeviceListHeader-test.tsx
+++ b/test/components/views/settings/devices/FilteredDeviceListHeader-test.tsx
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { render } from '@testing-library/react';
+import { fireEvent, render } from '@testing-library/react';
 import React from 'react';
 
 import FilteredDeviceListHeader from '../../../../../src/components/views/settings/devices/FilteredDeviceListHeader';
@@ -22,6 +22,8 @@ import FilteredDeviceListHeader from '../../../../../src/components/views/settin
 describe('<FilteredDeviceListHeader />', () => {
     const defaultProps = {
         selectedDeviceCount: 0,
+        isAllSelected: false,
+        toggleSelectAll: jest.fn(),
         children: <div>test</div>,
         ['data-testid']: 'test123',
     };
@@ -32,8 +34,21 @@ describe('<FilteredDeviceListHeader />', () => {
         expect(container).toMatchSnapshot();
     });
 
+    it('renders correctly when all devices are selected', () => {
+        const { container } = render(getComponent({ isAllSelected: true }));
+        expect(container).toMatchSnapshot();
+    });
+
     it('renders correctly when some devices are selected', () => {
         const { getByText } = render(getComponent({ selectedDeviceCount: 2 }));
         expect(getByText('2 sessions selected')).toBeTruthy();
     });
+
+    it('clicking checkbox toggles selection', () => {
+        const toggleSelectAll = jest.fn();
+        const { getByTestId } = render(getComponent({ toggleSelectAll }));
+        fireEvent.click(getByTestId('device-select-all-checkbox'));
+
+        expect(toggleSelectAll).toHaveBeenCalled();
+    });
 });
diff --git a/test/components/views/settings/devices/__snapshots__/FilteredDeviceListHeader-test.tsx.snap b/test/components/views/settings/devices/__snapshots__/FilteredDeviceListHeader-test.tsx.snap
index f474cca811..b8b2330ce9 100644
--- a/test/components/views/settings/devices/__snapshots__/FilteredDeviceListHeader-test.tsx.snap
+++ b/test/components/views/settings/devices/__snapshots__/FilteredDeviceListHeader-test.tsx.snap
@@ -1,11 +1,80 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`<FilteredDeviceListHeader /> renders correctly when no devices are selected 1`] = `
+exports[`<FilteredDeviceListHeader /> renders correctly when all devices are selected 1`] = `
 <div>
   <div
     class="mx_FilteredDeviceListHeader"
     data-testid="test123"
   >
+    <div
+      tabindex="0"
+    >
+      <span
+        class="mx_Checkbox mx_Checkbox_hasKind mx_Checkbox_kind_solid"
+      >
+        <input
+          aria-label="Deselect all"
+          checked=""
+          data-testid="device-select-all-checkbox"
+          id="device-select-all-checkbox"
+          type="checkbox"
+        />
+        <label
+          for="device-select-all-checkbox"
+        >
+          <div
+            class="mx_Checkbox_background"
+          >
+            <div
+              class="mx_Checkbox_checkmark"
+            />
+          </div>
+        </label>
+      </span>
+    </div>
+    <span
+      class="mx_FilteredDeviceListHeader_label"
+    >
+      Sessions
+    </span>
+    <div>
+      test
+    </div>
+  </div>
+</div>
+`;
+
+exports[`<FilteredDeviceListHeader /> renders correctly when no devices are selected 1`] = `
+<div>
+  <div
+    class="mx_FilteredDeviceListHeader"
+    data-testid="test123"
+  >
+    <div
+      tabindex="0"
+    >
+      <span
+        class="mx_Checkbox mx_Checkbox_hasKind mx_Checkbox_kind_solid"
+      >
+        <input
+          aria-label="Select all"
+          data-testid="device-select-all-checkbox"
+          id="device-select-all-checkbox"
+          type="checkbox"
+        />
+        <label
+          for="device-select-all-checkbox"
+        >
+          <div
+            class="mx_Checkbox_background"
+          >
+            <div
+              class="mx_Checkbox_checkmark"
+            />
+          </div>
+        </label>
+      </span>
+    </div>
     <span
       class="mx_FilteredDeviceListHeader_label"
     >
diff --git a/test/components/views/settings/tabs/user/SessionManagerTab-test.tsx b/test/components/views/settings/tabs/user/SessionManagerTab-test.tsx
index 669be2eb95..7210198772 100644
--- a/test/components/views/settings/tabs/user/SessionManagerTab-test.tsx
+++ b/test/components/views/settings/tabs/user/SessionManagerTab-test.tsx
@@ -38,10 +38,17 @@ import {
     getMockClientWithEventEmitter,
     mkPusher,
     mockClientMethodsUser,
+    mockPlatformPeg,
 } from '../../../../../test-utils';
 import Modal from '../../../../../../src/Modal';
 import LogoutDialog from '../../../../../../src/components/views/dialogs/LogoutDialog';
-import { DeviceWithVerification } from '../../../../../../src/components/views/settings/devices/types';
+import {
+    DeviceSecurityVariation,
+    DeviceWithVerification,
+} from '../../../../../../src/components/views/settings/devices/types';
+import { INACTIVE_DEVICE_AGE_MS } from '../../../../../../src/components/views/settings/devices/filter';
+
+mockPlatformPeg();
 
 describe('<SessionManagerTab />', () => {
     const aliceId = '@alice:server.org';
@@ -61,6 +68,11 @@ describe('<SessionManagerTab />', () => {
         last_seen_ts: Date.now() - 600000,
     };
 
+    const alicesInactiveDevice = {
+        device_id: 'alices_older_mobile_device',
+        last_seen_ts: Date.now() - (INACTIVE_DEVICE_AGE_MS + 1000),
+    };
+
     const mockCrossSigningInfo = {
         checkDeviceTrust: jest.fn(),
     };
@@ -108,11 +120,28 @@ describe('<SessionManagerTab />', () => {
         fireEvent.click(checkbox);
     };
 
+    const setFilter = async (
+        container: HTMLElement,
+        option: DeviceSecurityVariation | string,
+    ) => await act(async () => {
+        const dropdown = container.querySelector('[aria-label="Filter devices"]');
+
+        fireEvent.click(dropdown as Element);
+        // tick to let dropdown render
+        await flushPromisesWithFakeTimers();
+
+        fireEvent.click(container.querySelector(`#device-list-filter__${option}`) as Element);
+    });
+
     const isDeviceSelected = (
         getByTestId: ReturnType<typeof render>['getByTestId'],
         deviceId: DeviceWithVerification['device_id'],
     ): boolean => !!(getByTestId(`device-tile-checkbox-${deviceId}`) as HTMLInputElement).checked;
 
+    const isSelectAllChecked = (
+        getByTestId: ReturnType<typeof render>['getByTestId'],
+    ): boolean => !!(getByTestId('device-select-all-checkbox') as HTMLInputElement).checked;
+
     beforeEach(() => {
         jest.clearAllMocks();
         jest.spyOn(logger, 'error').mockRestore();
@@ -811,6 +840,96 @@ describe('<SessionManagerTab />', () => {
             // unselected
             expect(isDeviceSelected(getByTestId, alicesOlderMobileDevice.device_id)).toBeFalsy();
         });
+
+        describe('toggling select all', () => {
+            it('selects all sessions when there is not existing selection', async () => {
+                const { getByTestId, getByText } = render(getComponent());
+
+                await act(async () => {
+                    await flushPromisesWithFakeTimers();
+                });
+
+                fireEvent.click(getByTestId('device-select-all-checkbox'));
+
+                // header displayed correctly
+                expect(getByText('2 sessions selected')).toBeTruthy();
+                expect(isSelectAllChecked(getByTestId)).toBeTruthy();
+
+                // devices selected
+                expect(isDeviceSelected(getByTestId, alicesMobileDevice.device_id)).toBeTruthy();
+                expect(isDeviceSelected(getByTestId, alicesOlderMobileDevice.device_id)).toBeTruthy();
+            });
+
+            it('selects all sessions when some sessions are already selected', async () => {
+                const { getByTestId, getByText } = render(getComponent());
+
+                await act(async () => {
+                    await flushPromisesWithFakeTimers();
+                });
+
+                toggleDeviceSelection(getByTestId, alicesMobileDevice.device_id);
+
+                fireEvent.click(getByTestId('device-select-all-checkbox'));
+
+                // header displayed correctly
+                expect(getByText('2 sessions selected')).toBeTruthy();
+                expect(isSelectAllChecked(getByTestId)).toBeTruthy();
+
+                // devices selected
+                expect(isDeviceSelected(getByTestId, alicesMobileDevice.device_id)).toBeTruthy();
+                expect(isDeviceSelected(getByTestId, alicesOlderMobileDevice.device_id)).toBeTruthy();
+            });
+
+            it('deselects all sessions when all sessions are selected', async () => {
+                const { getByTestId, getByText } = render(getComponent());
+
+                await act(async () => {
+                    await flushPromisesWithFakeTimers();
+                });
+
+                fireEvent.click(getByTestId('device-select-all-checkbox'));
+
+                // header displayed correctly
+                expect(getByText('2 sessions selected')).toBeTruthy();
+                expect(isSelectAllChecked(getByTestId)).toBeTruthy();
+
+                // devices selected
+                expect(isDeviceSelected(getByTestId, alicesMobileDevice.device_id)).toBeTruthy();
+                expect(isDeviceSelected(getByTestId, alicesOlderMobileDevice.device_id)).toBeTruthy();
+            });
+
+            it('selects only sessions that are part of the active filter', async () => {
+                mockClient.getDevices.mockResolvedValue({ devices: [
+                    alicesDevice,
+                    alicesMobileDevice,
+                    alicesInactiveDevice,
+                ] });
+                const { getByTestId, container } = render(getComponent());
+
+                await act(async () => {
+                    await flushPromisesWithFakeTimers();
+                });
+
+                // filter for inactive sessions
+                await setFilter(container, DeviceSecurityVariation.Inactive);
+
+                // select all inactive sessions
+                fireEvent.click(getByTestId('device-select-all-checkbox'));
+
+                expect(isSelectAllChecked(getByTestId)).toBeTruthy();
+
+                // sign out of all selected sessions
+                fireEvent.click(getByTestId('sign-out-selection-cta'));
+
+                // only called with session from active filter
+                expect(mockClient.deleteMultipleDevices).toHaveBeenCalledWith(
+                    [
+                        alicesInactiveDevice.device_id,
+                    ],
+                    undefined,
+                );
+            });
+        });
     });
 
     it("lets you change the pusher state", async () => {
diff --git a/test/components/views/settings/tabs/user/__snapshots__/SessionManagerTab-test.tsx.snap b/test/components/views/settings/tabs/user/__snapshots__/SessionManagerTab-test.tsx.snap
index 32af1a3fa6..89d4c1db84 100644
--- a/test/components/views/settings/tabs/user/__snapshots__/SessionManagerTab-test.tsx.snap
+++ b/test/components/views/settings/tabs/user/__snapshots__/SessionManagerTab-test.tsx.snap
@@ -19,6 +19,31 @@ exports[`<SessionManagerTab /> goes to filtered list from security recommendatio
 <div
   class="mx_FilteredDeviceListHeader"
 >
+  <div
+    tabindex="0"
+  >
+    <span
+      class="mx_Checkbox mx_Checkbox_hasKind mx_Checkbox_kind_solid"
+    >
+      <input
+        aria-label="Select all"
+        data-testid="device-select-all-checkbox"
+        id="device-select-all-checkbox"
+        type="checkbox"
+      />
+      <label
+        for="device-select-all-checkbox"
+      >
+        <div
+          class="mx_Checkbox_background"
+        >
+          <div
+            class="mx_Checkbox_checkmark"
+          />
+        </div>
+      </label>
+    </span>
+  </div>
   <span
     class="mx_FilteredDeviceListHeader_label"
   >