diff --git a/docs/pages/api-docs/mobile-stepper.json b/docs/pages/api-docs/mobile-stepper.json
index 589b8428827995..881c9b01f41cd5 100644
--- a/docs/pages/api-docs/mobile-stepper.json
+++ b/docs/pages/api-docs/mobile-stepper.json
@@ -13,6 +13,7 @@
       },
       "default": "'bottom'"
     },
+    "sx": { "type": { "name": "object" } },
     "variant": {
       "type": {
         "name": "enum",
@@ -41,6 +42,6 @@
   "filename": "/packages/material-ui/src/MobileStepper/MobileStepper.js",
   "inheritance": { "component": "Paper", "pathname": "/api/paper/" },
   "demos": "<ul><li><a href=\"/components/steppers/\">Steppers</a></li></ul>",
-  "styledComponent": false,
+  "styledComponent": true,
   "cssComponent": false
 }
diff --git a/docs/translations/api-docs/mobile-stepper/mobile-stepper.json b/docs/translations/api-docs/mobile-stepper/mobile-stepper.json
index fbb4937f610891..bf775aa47ea017 100644
--- a/docs/translations/api-docs/mobile-stepper/mobile-stepper.json
+++ b/docs/translations/api-docs/mobile-stepper/mobile-stepper.json
@@ -8,6 +8,7 @@
     "nextButton": "A next button element. For instance, it can be a <code>Button</code> or an <code>IconButton</code>.",
     "position": "Set the positioning type.",
     "steps": "The total steps.",
+    "sx": "The system prop that allows defining system overrides as well as additional CSS styles. See the <a href=\"/system/basics/#the-sx-prop\">`sx` page</a> for more details.",
     "variant": "The variant to use."
   },
   "classDescriptions": {
diff --git a/packages/material-ui/src/MobileStepper/MobileStepper.d.ts b/packages/material-ui/src/MobileStepper/MobileStepper.d.ts
index 42919b12821756..67c17ff2f0e660 100644
--- a/packages/material-ui/src/MobileStepper/MobileStepper.d.ts
+++ b/packages/material-ui/src/MobileStepper/MobileStepper.d.ts
@@ -1,5 +1,6 @@
 import * as React from 'react';
-import { InternalStandardProps as StandardProps } from '..';
+import { SxProps } from '@material-ui/system';
+import { InternalStandardProps as StandardProps, Theme } from '..';
 import { PaperProps } from '../Paper';
 import { LinearProgressProps } from '../LinearProgress';
 
@@ -52,6 +53,10 @@ export interface MobileStepperProps extends StandardProps<PaperProps, 'children'
    * The total steps.
    */
   steps: number;
+  /**
+   * The system prop that allows defining system overrides as well as additional CSS styles.
+   */
+  sx?: SxProps<Theme>;
   /**
    * The variant to use.
    * @default 'dots'
diff --git a/packages/material-ui/src/MobileStepper/MobileStepper.js b/packages/material-ui/src/MobileStepper/MobileStepper.js
index 081fc410987dec..6659cf563deb7f 100644
--- a/packages/material-ui/src/MobileStepper/MobileStepper.js
+++ b/packages/material-ui/src/MobileStepper/MobileStepper.js
@@ -1,47 +1,101 @@
 import * as React from 'react';
 import PropTypes from 'prop-types';
 import clsx from 'clsx';
-import { integerPropType } from '@material-ui/utils';
-import withStyles from '../styles/withStyles';
+import { integerPropType, deepmerge } from '@material-ui/utils';
+import { unstable_composeClasses as composeClasses } from '@material-ui/unstyled';
 import Paper from '../Paper';
 import capitalize from '../utils/capitalize';
 import LinearProgress from '../LinearProgress';
 
-export const styles = (theme) => ({
-  /* Styles applied to the root element. */
-  root: {
-    display: 'flex',
-    flexDirection: 'row',
-    justifyContent: 'space-between',
-    alignItems: 'center',
-    background: theme.palette.background.default,
-    padding: 8,
+import useThemeProps from '../styles/useThemeProps';
+import experimentalStyled from '../styles/experimentalStyled';
+import mobileStepperClasses, { getMobileStepperUtilityClass } from './mobileStepperClasses';
+
+const overridesResolver = (props, styles) => {
+  const { styleProps } = props;
+
+  return deepmerge(
+    {
+      ...styles[`position${capitalize(styleProps.position)}`],
+      [`& .${mobileStepperClasses.dots}`]: styles.dots,
+      [`& .${mobileStepperClasses.dot}`]: {
+        ...styles.dot,
+        ...(styleProps.dotActive && styles.dotActive),
+      },
+      [`& .${mobileStepperClasses.dotActive}`]: styles.dotActive,
+      [`& .${mobileStepperClasses.progress}`]: styles.progress,
+    },
+    styles.root || {},
+  );
+};
+
+const useUtilityClasses = (styleProps) => {
+  const { classes, position } = styleProps;
+
+  const slots = {
+    root: ['root', `position${capitalize(position)}`],
+    dots: ['dots'],
+    dot: ['dot'],
+    dotActive: ['dotActive'],
+    progress: ['progress'],
+  };
+
+  return composeClasses(slots, getMobileStepperUtilityClass, classes);
+};
+
+const MobileStepperRoot = experimentalStyled(
+  Paper,
+  {},
+  {
+    name: 'MuiMobileStepper',
+    slot: 'Root',
+    overridesResolver,
   },
+)(({ theme, styleProps }) => ({
+  /* Styles applied to the root element. */
+  display: 'flex',
+  flexDirection: 'row',
+  justifyContent: 'space-between',
+  alignItems: 'center',
+  background: theme.palette.background.default,
+  padding: 8,
   /* Styles applied to the root element if `position="bottom"`. */
-  positionBottom: {
+  ...(styleProps.position === 'bottom' && {
     position: 'fixed',
     bottom: 0,
     left: 0,
     right: 0,
     zIndex: theme.zIndex.mobileStepper,
-  },
+  }),
   /* Styles applied to the root element if `position="top"`. */
-  positionTop: {
+  ...(styleProps.position === 'top' && {
     position: 'fixed',
     top: 0,
     left: 0,
     right: 0,
     zIndex: theme.zIndex.mobileStepper,
-  },
-  /* Styles applied to the root element if `position="static"`. */
-  positionStatic: {},
+  }),
+}));
+
+const MobileStepperDots = experimentalStyled(
+  'div',
+  {},
+  { name: 'MuiMobileStepper', slot: 'Dots' },
+)(({ styleProps }) => ({
   /* Styles applied to the dots container if `variant="dots"`. */
-  dots: {
+  ...(styleProps.variant === 'dots' && {
     display: 'flex',
     flexDirection: 'row',
-  },
+  }),
+}));
+
+const MobileStepperDot = experimentalStyled(
+  'div',
+  {},
+  { name: 'MuiMobileStepper', slot: 'Dot' },
+)(({ theme, styleProps }) => ({
   /* Styles applied to each dot if `variant="dots"`. */
-  dot: {
+  ...(styleProps.variant === 'dots' && {
     transition: theme.transitions.create('background-color', {
       duration: theme.transitions.duration.shortest,
     }),
@@ -50,22 +104,29 @@ export const styles = (theme) => ({
     width: 8,
     height: 8,
     margin: '0 2px',
-  },
-  /* Styles applied to a dot if `variant="dots"` and this is the active step. */
-  dotActive: {
-    backgroundColor: theme.palette.primary.main,
-  },
+    /* Styles applied to a dot if `variant="dots"` and this is the active step. */
+    ...(styleProps.dotActive && {
+      backgroundColor: theme.palette.primary.main,
+    }),
+  }),
+}));
+
+const MobileStepperProgress = experimentalStyled(
+  LinearProgress,
+  {},
+  { name: 'MuiMobileStepper', slot: 'Progress' },
+)(({ styleProps }) => ({
   /* Styles applied to the Linear Progress component if `variant="progress"`. */
-  progress: {
+  ...(styleProps.variant === 'progress' && {
     width: '50%',
-  },
-});
+  }),
+}));
 
-const MobileStepper = React.forwardRef(function MobileStepper(props, ref) {
+const MobileStepper = React.forwardRef(function MobileStepper(inProps, ref) {
+  const props = useThemeProps({ props: inProps, name: 'MuiMobileStepper' });
   const {
     activeStep = 0,
     backButton,
-    classes,
     className,
     LinearProgressProps,
     nextButton,
@@ -75,12 +136,22 @@ const MobileStepper = React.forwardRef(function MobileStepper(props, ref) {
     ...other
   } = props;
 
+  const styleProps = {
+    ...props,
+    activeStep,
+    position,
+    variant,
+  };
+
+  const classes = useUtilityClasses(styleProps);
+
   return (
-    <Paper
+    <MobileStepperRoot
       square
       elevation={0}
-      className={clsx(classes.root, classes[`position${capitalize(position)}`], className)}
+      className={clsx(classes.root, className)}
       ref={ref}
+      styleProps={styleProps}
       {...other}
     >
       {backButton}
@@ -91,20 +162,20 @@ const MobileStepper = React.forwardRef(function MobileStepper(props, ref) {
       )}
 
       {variant === 'dots' && (
-        <div className={classes.dots}>
+        <MobileStepperDots styleProps={styleProps} className={classes.dots}>
           {[...new Array(steps)].map((_, index) => (
-            <div
+            <MobileStepperDot
               key={index}
-              className={clsx(classes.dot, {
-                [classes.dotActive]: index === activeStep,
-              })}
+              className={clsx(classes.dot, { [classes.dotActive]: index === activeStep })}
+              styleProps={{ ...styleProps, dotActive: index === activeStep }}
             />
           ))}
-        </div>
+        </MobileStepperDots>
       )}
 
       {variant === 'progress' && (
-        <LinearProgress
+        <MobileStepperProgress
+          styleProps={styleProps}
           className={classes.progress}
           variant="determinate"
           value={Math.ceil((activeStep / (steps - 1)) * 100)}
@@ -113,7 +184,7 @@ const MobileStepper = React.forwardRef(function MobileStepper(props, ref) {
       )}
 
       {nextButton}
-    </Paper>
+    </MobileStepperRoot>
   );
 });
 
@@ -157,6 +228,10 @@ MobileStepper.propTypes /* remove-proptypes */ = {
    * The total steps.
    */
   steps: integerPropType.isRequired,
+  /**
+   * The system prop that allows defining system overrides as well as additional CSS styles.
+   */
+  sx: PropTypes.object,
   /**
    * The variant to use.
    * @default 'dots'
@@ -164,4 +239,4 @@ MobileStepper.propTypes /* remove-proptypes */ = {
   variant: PropTypes.oneOf(['dots', 'progress', 'text']),
 };
 
-export default withStyles(styles, { name: 'MuiMobileStepper' })(MobileStepper);
+export default MobileStepper;
diff --git a/packages/material-ui/src/MobileStepper/MobileStepper.test.js b/packages/material-ui/src/MobileStepper/MobileStepper.test.js
index 9fa6c4980d351e..98c65046634ec7 100644
--- a/packages/material-ui/src/MobileStepper/MobileStepper.test.js
+++ b/packages/material-ui/src/MobileStepper/MobileStepper.test.js
@@ -1,22 +1,15 @@
 import * as React from 'react';
 import { expect } from 'chai';
-import {
-  getClasses,
-  createMount,
-  createClientRender,
-  describeConformance,
-  screen,
-} from 'test/utils';
-import KeyboardArrowLeft from '../internal/svg-icons/KeyboardArrowLeft';
+import { createMount, createClientRender, describeConformanceV5, screen } from 'test/utils';
+import Paper, { paperClasses } from '@material-ui/core/Paper';
+import Button from '@material-ui/core/Button';
+import MobileStepper, { mobileStepperClasses as classes } from '@material-ui/core/MobileStepper';
 import KeyboardArrowRight from '../internal/svg-icons/KeyboardArrowRight';
-import Paper, { paperClasses } from '../Paper';
-import Button from '../Button/Button';
-import MobileStepper from './MobileStepper';
+import KeyboardArrowLeft from '../internal/svg-icons/KeyboardArrowLeft';
 
 describe('<MobileStepper />', () => {
   const mount = createMount();
   const render = createClientRender();
-  let classes;
   const defaultProps = {
     steps: 2,
     nextButton: (
@@ -33,16 +26,17 @@ describe('<MobileStepper />', () => {
     ),
   };
 
-  before(() => {
-    classes = getClasses(<MobileStepper {...defaultProps} />);
-  });
-
-  describeConformance(<MobileStepper {...defaultProps} />, () => ({
+  describeConformanceV5(<MobileStepper {...defaultProps} />, () => ({
     classes,
     inheritComponent: Paper,
     mount,
+    render,
+    muiName: 'MuiMobileStepper',
+    testVariantProps: { variant: 'progress' },
+    testDeepOverrides: { slotName: 'dot', slotClassName: classes.dot },
+    testStateOverrides: { prop: 'position', value: 'static', styleKey: 'positionStatic' },
     refInstanceof: window.HTMLDivElement,
-    skip: ['componentProp'],
+    skip: ['componentProp', 'componentsProp'],
   }));
 
   it('should render a Paper with 0 elevation', () => {
diff --git a/packages/material-ui/src/MobileStepper/index.d.ts b/packages/material-ui/src/MobileStepper/index.d.ts
index fb4b8e3425069f..3d89f5f994bd51 100644
--- a/packages/material-ui/src/MobileStepper/index.d.ts
+++ b/packages/material-ui/src/MobileStepper/index.d.ts
@@ -1,2 +1,5 @@
 export { default } from './MobileStepper';
 export * from './MobileStepper';
+
+export { default as mobileStepperClasses } from './mobileStepperClasses';
+export * from './mobileStepperClasses';
diff --git a/packages/material-ui/src/MobileStepper/index.js b/packages/material-ui/src/MobileStepper/index.js
index 3d03d2a032e9e6..ef2f34beedbca9 100644
--- a/packages/material-ui/src/MobileStepper/index.js
+++ b/packages/material-ui/src/MobileStepper/index.js
@@ -1 +1,4 @@
 export { default } from './MobileStepper';
+
+export { default as mobileStepperClasses } from './mobileStepperClasses';
+export * from './mobileStepperClasses';
diff --git a/packages/material-ui/src/MobileStepper/mobileStepperClasses.d.ts b/packages/material-ui/src/MobileStepper/mobileStepperClasses.d.ts
new file mode 100644
index 00000000000000..40222a7672fd26
--- /dev/null
+++ b/packages/material-ui/src/MobileStepper/mobileStepperClasses.d.ts
@@ -0,0 +1,7 @@
+import { MobileStepperClassKey } from './MobileStepper';
+
+declare const mobileStepperClasses: Record<MobileStepperClassKey, string>;
+
+export function getMobileStepperUtilityClass(slot: string): string;
+
+export default mobileStepperClasses;
diff --git a/packages/material-ui/src/MobileStepper/mobileStepperClasses.js b/packages/material-ui/src/MobileStepper/mobileStepperClasses.js
new file mode 100644
index 00000000000000..a15e3d2e9933f7
--- /dev/null
+++ b/packages/material-ui/src/MobileStepper/mobileStepperClasses.js
@@ -0,0 +1,18 @@
+import { generateUtilityClass, generateUtilityClasses } from '@material-ui/unstyled';
+
+export function getMobileStepperUtilityClass(slot) {
+  return generateUtilityClass('MuiMobileStepper', slot);
+}
+
+const mobileStepperClasses = generateUtilityClasses('MuiMobileStepper', [
+  'root',
+  'positionBottom',
+  'positionTop',
+  'positionStatic',
+  'dots',
+  'dot',
+  'dotActive',
+  'progress',
+]);
+
+export default mobileStepperClasses;