diff --git a/ui/src/common/SelectLibraryInput.jsx b/ui/src/common/SelectLibraryInput.jsx
index 4d34fd822..4825693ea 100644
--- a/ui/src/common/SelectLibraryInput.jsx
+++ b/ui/src/common/SelectLibraryInput.jsx
@@ -8,8 +8,9 @@ import {
   ListItemIcon,
   ListItemText,
   Typography,
+  Box,
 } from '@material-ui/core'
-import { useGetList } from 'react-admin'
+import { useGetList, useTranslate } from 'react-admin'
 import PropTypes from 'prop-types'
 import { makeStyles } from '@material-ui/core'
 
@@ -18,6 +19,17 @@ const useStyles = makeStyles((theme) => ({
     width: '960px', // MD breakpoint width
     maxWidth: '100%',
   },
+  headerContainer: {
+    display: 'flex',
+    alignItems: 'center',
+    marginBottom: theme.spacing(1),
+    paddingLeft: theme.spacing(1),
+  },
+  masterCheckbox: {
+    padding: '7px', // Match the default Material-UI checkbox padding
+    marginLeft: '-9px', // Negative margin to align with FormControlLabel checkboxes
+    marginRight: theme.spacing(1),
+  },
   libraryList: {
     height: '120px', // 3 rows of libraries
     overflow: 'auto',
@@ -72,6 +84,7 @@ const LibraryListItem = ({ library, isSelected, onToggle }) => {
 
 export const SelectLibraryInput = ({ onChange, value = [] }) => {
   const classes = useStyles()
+  const translate = useTranslate()
   const [selectedLibraryIds, setSelectedLibraryIds] = useState([])
 
   const { ids, data } = useGetList(
@@ -109,8 +122,35 @@ export const SelectLibraryInput = ({ onChange, value = [] }) => {
     onChange(newSelection)
   }
 
+  const handleMasterCheckboxChange = () => {
+    const isAllSelected = selectedLibraryIds.length === options.length
+    const newSelection = isAllSelected ? [] : options.map((lib) => lib.id)
+
+    setSelectedLibraryIds(newSelection)
+    onChange(newSelection)
+  }
+
+  const selectedCount = selectedLibraryIds.length
+  const totalCount = options.length
+  const isAllSelected = selectedCount === totalCount && totalCount > 0
+  const isIndeterminate = selectedCount > 0 && selectedCount < totalCount
+
   return (
     <div className={classes.root}>
+      {options.length > 1 && (
+        <Box className={classes.headerContainer}>
+          <Checkbox
+            checked={isAllSelected}
+            indeterminate={isIndeterminate}
+            onChange={handleMasterCheckboxChange}
+            size="small"
+            className={classes.masterCheckbox}
+          />
+          <Typography variant="body2">
+            {translate('resources.user.message.selectAllLibraries')}
+          </Typography>
+        </Box>
+      )}
       <List className={classes.libraryList}>
         {options.length === 0 ? (
           <EmptyLibraryMessage />
diff --git a/ui/src/common/SelectLibraryInput.test.jsx b/ui/src/common/SelectLibraryInput.test.jsx
index 706ece428..35e640591 100644
--- a/ui/src/common/SelectLibraryInput.test.jsx
+++ b/ui/src/common/SelectLibraryInput.test.jsx
@@ -4,9 +4,50 @@ import { SelectLibraryInput } from './SelectLibraryInput'
 import { useGetList } from 'react-admin'
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
 
+// Mock Material-UI components
+vi.mock('@material-ui/core', () => ({
+  List: ({ children }) => <div>{children}</div>,
+  ListItem: ({ children, button, onClick, dense, className }) => (
+    <button onClick={onClick} className={className}>
+      {children}
+    </button>
+  ),
+  ListItemIcon: ({ children }) => <span>{children}</span>,
+  ListItemText: ({ primary }) => <span>{primary}</span>,
+  Typography: ({ children, variant }) => <span>{children}</span>,
+  Box: ({ children, className }) => <div className={className}>{children}</div>,
+  Checkbox: ({
+    checked,
+    indeterminate,
+    onChange,
+    size,
+    className,
+    ...props
+  }) => (
+    <input
+      type="checkbox"
+      checked={checked}
+      ref={(el) => {
+        if (el) el.indeterminate = indeterminate
+      }}
+      onChange={onChange}
+      className={className}
+      {...props}
+    />
+  ),
+  makeStyles: () => () => ({}),
+}))
+
+// Mock Material-UI icons
+vi.mock('@material-ui/icons', () => ({
+  CheckBox: () => <span>☑</span>,
+  CheckBoxOutlineBlank: () => <span>☐</span>,
+}))
+
 // Mock the react-admin hook
 vi.mock('react-admin', () => ({
   useGetList: vi.fn(),
+  useTranslate: vi.fn(() => (key) => key), // Simple translation mock
 }))
 
 describe('<SelectLibraryInput />', () => {
@@ -60,8 +101,9 @@ describe('<SelectLibraryInput />', () => {
     })
     render(<SelectLibraryInput onChange={mockOnChange} value={[]} />)
 
-    // First test - click to select
-    fireEvent.click(screen.getAllByRole('button')[0]) // Click first list item
+    // Find the library buttons by their text content
+    const library1Button = screen.getByText('Library 1').closest('button')
+    fireEvent.click(library1Button)
     expect(mockOnChange).toHaveBeenCalledWith(['1'])
 
     // Clean up to avoid DOM duplication
@@ -75,8 +117,11 @@ describe('<SelectLibraryInput />', () => {
     })
     render(<SelectLibraryInput onChange={mockOnChange} value={['1']} />)
 
-    // Second test - click to deselect
-    fireEvent.click(screen.getAllByRole('button')[0]) // Click first list item again
+    // Find the library button again and click to deselect
+    const library1ButtonDeselect = screen
+      .getByText('Library 1')
+      .closest('button')
+    fireEvent.click(library1ButtonDeselect)
     expect(mockOnChange).toHaveBeenCalledWith([])
   })
 
@@ -96,8 +141,9 @@ describe('<SelectLibraryInput />', () => {
 
     // Check that checkbox for Library 1 is checked
     const checkboxes = screen.getAllByRole('checkbox')
-    expect(checkboxes[0].checked).toBe(true)
-    expect(checkboxes[1].checked).toBe(false)
+    // With master checkbox, individual checkboxes start at index 1
+    expect(checkboxes[1].checked).toBe(true) // Library 1
+    expect(checkboxes[2].checked).toBe(false) // Library 2
   })
 
   it('should handle value as array of objects', () => {
@@ -116,7 +162,101 @@ describe('<SelectLibraryInput />', () => {
 
     // Check that checkbox for Library 2 is checked
     const checkboxes = screen.getAllByRole('checkbox')
-    expect(checkboxes[0].checked).toBe(false)
-    expect(checkboxes[1].checked).toBe(true)
+    // With master checkbox, index shifts by 1
+    expect(checkboxes[1].checked).toBe(false) // Library 1
+    expect(checkboxes[2].checked).toBe(true) // Library 2
+  })
+
+  it('should render master checkbox when there are multiple libraries', () => {
+    // Mock libraries
+    const mockLibraries = {
+      1: { id: '1', name: 'Library 1' },
+      2: { id: '2', name: 'Library 2' },
+    }
+    useGetList.mockReturnValue({
+      ids: ['1', '2'],
+      data: mockLibraries,
+    })
+
+    render(<SelectLibraryInput onChange={mockOnChange} value={[]} />)
+
+    // Should render master checkbox plus individual checkboxes
+    const checkboxes = screen.getAllByRole('checkbox')
+    expect(checkboxes).toHaveLength(3) // 1 master + 2 individual
+    expect(
+      screen.getByText('resources.user.message.selectAllLibraries'),
+    ).not.toBeNull()
+  })
+
+  it('should not render master checkbox when there is only one library', () => {
+    // Mock single library
+    const mockLibraries = {
+      1: { id: '1', name: 'Library 1' },
+    }
+    useGetList.mockReturnValue({
+      ids: ['1'],
+      data: mockLibraries,
+    })
+
+    render(<SelectLibraryInput onChange={mockOnChange} value={[]} />)
+
+    // Should render only individual checkbox
+    const checkboxes = screen.getAllByRole('checkbox')
+    expect(checkboxes).toHaveLength(1) // Only 1 individual checkbox
+  })
+
+  it('should handle master checkbox selection and deselection', () => {
+    // Mock libraries
+    const mockLibraries = {
+      1: { id: '1', name: 'Library 1' },
+      2: { id: '2', name: 'Library 2' },
+    }
+    useGetList.mockReturnValue({
+      ids: ['1', '2'],
+      data: mockLibraries,
+    })
+
+    render(<SelectLibraryInput onChange={mockOnChange} value={[]} />)
+
+    const checkboxes = screen.getAllByRole('checkbox')
+    const masterCheckbox = checkboxes[0] // Master is first
+
+    // Click master checkbox to select all
+    fireEvent.click(masterCheckbox)
+    expect(mockOnChange).toHaveBeenCalledWith(['1', '2'])
+
+    // Clean up and test deselect all
+    cleanup()
+    mockOnChange.mockClear()
+
+    render(<SelectLibraryInput onChange={mockOnChange} value={['1', '2']} />)
+    const checkboxes2 = screen.getAllByRole('checkbox')
+    const masterCheckbox2 = checkboxes2[0]
+
+    // Click master checkbox to deselect all
+    fireEvent.click(masterCheckbox2)
+    expect(mockOnChange).toHaveBeenCalledWith([])
+  })
+
+  it('should show master checkbox as indeterminate when some libraries are selected', () => {
+    // Mock libraries
+    const mockLibraries = {
+      1: { id: '1', name: 'Library 1' },
+      2: { id: '2', name: 'Library 2' },
+    }
+    useGetList.mockReturnValue({
+      ids: ['1', '2'],
+      data: mockLibraries,
+    })
+
+    render(<SelectLibraryInput onChange={mockOnChange} value={['1']} />)
+
+    const checkboxes = screen.getAllByRole('checkbox')
+    const masterCheckbox = checkboxes[0] // Master is first
+
+    // Master checkbox should not be checked when only some libraries are selected
+    expect(masterCheckbox.checked).toBe(false)
+    // Note: Testing indeterminate property directly through JSDOM can be unreliable
+    // The important behavior is that it's not checked when only some are selected
   })
 })
diff --git a/ui/src/i18n/en.json b/ui/src/i18n/en.json
index 9525b878d..72cc3adb9 100644
--- a/ui/src/i18n/en.json
+++ b/ui/src/i18n/en.json
@@ -166,9 +166,8 @@
       },
       "message": {
         "listenBrainzToken": "Enter your ListenBrainz user token.",
-        "clickHereForToken": "Click here to get your token"
-      },
-      "messages": {
+        "clickHereForToken": "Click here to get your token",
+        "selectAllLibraries": "Select all libraries",
         "adminAutoLibraries": "Admin users automatically have access to all libraries"
       }
     },
diff --git a/ui/src/user/UserCreate.jsx b/ui/src/user/UserCreate.jsx
index 182f66ab5..ee1fa5f79 100644
--- a/ui/src/user/UserCreate.jsx
+++ b/ui/src/user/UserCreate.jsx
@@ -95,7 +95,7 @@ const UserCreate = (props) => {
                   color="textSecondary"
                   style={{ marginTop: 16, marginBottom: 16 }}
                 >
-                  {translate('resources.user.messages.adminAutoLibraries')}
+                  {translate('resources.user.message.adminAutoLibraries')}
                 </Typography>
               )}
             </>
diff --git a/ui/src/user/UserEdit.jsx b/ui/src/user/UserEdit.jsx
index 9401f8f7c..3406aa4c4 100644
--- a/ui/src/user/UserEdit.jsx
+++ b/ui/src/user/UserEdit.jsx
@@ -171,7 +171,7 @@ const UserEdit = (props) => {
                     color="textSecondary"
                     style={{ marginTop: 16, marginBottom: 16 }}
                   >
-                    {translate('resources.user.messages.adminAutoLibraries')}
+                    {translate('resources.user.message.adminAutoLibraries')}
                   </Typography>
                 )}
               </>