diff --git a/docs/pages/api-docs/breadcrumbs.json b/docs/pages/api-docs/breadcrumbs.json
index 3b850e5caa84f8..9caa03a2639b55 100644
--- a/docs/pages/api-docs/breadcrumbs.json
+++ b/docs/pages/api-docs/breadcrumbs.json
@@ -7,7 +7,8 @@
     "itemsAfterCollapse": { "type": { "name": "number" }, "default": "1" },
     "itemsBeforeCollapse": { "type": { "name": "number" }, "default": "1" },
     "maxItems": { "type": { "name": "number" }, "default": "8" },
-    "separator": { "type": { "name": "node" }, "default": "'/'" }
+    "separator": { "type": { "name": "node" }, "default": "'/'" },
+    "sx": { "type": { "name": "object" } }
   },
   "name": "Breadcrumbs",
   "styles": {
@@ -20,6 +21,6 @@
   "filename": "/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js",
   "inheritance": null,
   "demos": "<ul><li><a href=\"/components/breadcrumbs/\">Breadcrumbs</a></li></ul>",
-  "styledComponent": false,
+  "styledComponent": true,
   "cssComponent": false
 }
diff --git a/docs/translations/api-docs/breadcrumbs/breadcrumbs.json b/docs/translations/api-docs/breadcrumbs/breadcrumbs.json
index bbcf7474ae8905..e4aaaa78030013 100644
--- a/docs/translations/api-docs/breadcrumbs/breadcrumbs.json
+++ b/docs/translations/api-docs/breadcrumbs/breadcrumbs.json
@@ -8,7 +8,8 @@
     "itemsAfterCollapse": "If max items is exceeded, the number of items to show after the ellipsis.",
     "itemsBeforeCollapse": "If max items is exceeded, the number of items to show before the ellipsis.",
     "maxItems": "Specifies the maximum number of breadcrumbs to display. When there are more than the maximum number, only the first <code>itemsBeforeCollapse</code> and last <code>itemsAfterCollapse</code> will be shown, with an ellipsis in between.",
-    "separator": "Custom separator node."
+    "separator": "Custom separator node.",
+    "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."
   },
   "classDescriptions": {
     "root": { "description": "Styles applied to the root element." },
diff --git a/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.js b/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.js
index 046a79ae6654a8..4390f3108da474 100644
--- a/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.js
+++ b/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.js
@@ -1,52 +1,89 @@
 import * as React from 'react';
 import PropTypes from 'prop-types';
-import withStyles from '../styles/withStyles';
+import { unstable_composeClasses as composeClasses } from '@material-ui/unstyled';
+import experimentalStyled from '../styles/experimentalStyled';
 import { emphasize } from '../styles/colorManipulator';
 import MoreHorizIcon from '../internal/svg-icons/MoreHoriz';
 import ButtonBase from '../ButtonBase';
+import { getBreadcrumbCollapsedUtilityClass } from './breadcrumbCollapsedClasses';
 
-const styles = (theme) => ({
-  button: {
-    display: 'flex',
-    marginLeft: theme.spacing(0.5),
-    marginRight: theme.spacing(0.5),
-    backgroundColor: theme.palette.grey[100],
-    color: theme.palette.grey[700],
-    borderRadius: 2,
-    '&:hover, &:focus': {
-      backgroundColor: theme.palette.grey[200],
-    },
-    '&:active': {
-      boxShadow: theme.shadows[0],
-      backgroundColor: emphasize(theme.palette.grey[200], 0.12),
-    },
+const useUtilityClasses = (styleProps) => {
+  const { classes } = styleProps;
+
+  const slots = {
+    button: ['button'],
+    icon: ['icon'],
+  };
+
+  return composeClasses(slots, getBreadcrumbCollapsedUtilityClass, classes);
+};
+
+const BreadcrumbCollapsedButton = experimentalStyled(
+  ButtonBase,
+  {},
+  {
+    name: 'PrivateBreadcrumbCollapsed',
+    slot: 'Button',
   },
-  icon: {
-    width: 24,
-    height: 16,
+)(({ theme }) => ({
+  display: 'flex',
+  marginLeft: theme.spacing(0.5),
+  marginRight: theme.spacing(0.5),
+  ...(theme.palette.mode === 'light'
+    ? { backgroundColor: theme.palette.grey[100], color: theme.palette.grey[700] }
+    : { backgroundColor: theme.palette.grey[700], color: theme.palette.grey[100] }),
+  borderRadius: 2,
+  '&:hover, &:focus': {
+    ...(theme.palette.mode === 'light'
+      ? { backgroundColor: theme.palette.grey[200] }
+      : { backgroundColor: theme.palette.grey[600] }),
+  },
+  '&:active': {
+    boxShadow: theme.shadows[0],
+    ...(theme.palette.mode === 'light'
+      ? { backgroundColor: emphasize(theme.palette.grey[200], 0.12) }
+      : { backgroundColor: emphasize(theme.palette.grey[600], 0.12) }),
+  },
+}));
+
+const BreadcrumbCollapsedIcon = experimentalStyled(
+  MoreHorizIcon,
+  {},
+  {
+    name: 'PrivateBreadcrumbCollapsed',
+    slot: 'Icon',
   },
+)({
+  width: 24,
+  height: 16,
 });
 
 /**
  * @ignore - internal component.
  */
 function BreadcrumbCollapsed(props) {
-  const { classes, ...other } = props;
+  const styleProps = props;
+  const classes = useUtilityClasses(styleProps);
 
   return (
     <li>
-      <ButtonBase className={classes.button} focusRipple {...other}>
-        <MoreHorizIcon className={classes.icon} />
-      </ButtonBase>
+      <BreadcrumbCollapsedButton
+        className={classes.button}
+        focusRipple
+        {...props}
+        styleProps={styleProps}
+      >
+        <BreadcrumbCollapsedIcon className={classes.icon} styleProps={styleProps} />
+      </BreadcrumbCollapsedButton>
     </li>
   );
 }
 
 BreadcrumbCollapsed.propTypes = {
   /**
-   * @ignore
+   * The system prop that allows defining system overrides as well as additional CSS styles.
    */
-  classes: PropTypes.object.isRequired,
+  sx: PropTypes.object,
 };
 
-export default withStyles(styles, { name: 'PrivateBreadcrumbCollapsed' })(BreadcrumbCollapsed);
+export default BreadcrumbCollapsed;
diff --git a/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.test.js b/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.test.js
index 796026fff7ca2b..43ad3c5f2c43b7 100644
--- a/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.test.js
+++ b/packages/material-ui/src/Breadcrumbs/BreadcrumbCollapsed.test.js
@@ -1,17 +1,13 @@
 import * as React from 'react';
 import { expect } from 'chai';
 import { spy } from 'sinon';
-import { getClasses, fireEvent, createClientRender } from 'test/utils';
+import { fireEvent, createClientRender } from 'test/utils';
 import BreadcrumbCollapsed from './BreadcrumbCollapsed';
+import classes from './breadcrumbCollapsedClasses';
 
 describe('<BreadcrumbCollapsed />', () => {
-  let classes;
   const render = createClientRender();
 
-  before(() => {
-    classes = getClasses(<BreadcrumbCollapsed />);
-  });
-
   it('should render an icon', () => {
     const { container, getByRole } = render(<BreadcrumbCollapsed />);
 
diff --git a/packages/material-ui/src/Breadcrumbs/Breadcrumbs.d.ts b/packages/material-ui/src/Breadcrumbs/Breadcrumbs.d.ts
index 42fda3ca4616d9..1bd6b5553ed6c0 100644
--- a/packages/material-ui/src/Breadcrumbs/Breadcrumbs.d.ts
+++ b/packages/material-ui/src/Breadcrumbs/Breadcrumbs.d.ts
@@ -1,4 +1,6 @@
 import * as React from 'react';
+import { SxProps } from '@material-ui/system';
+import { Theme } from '@material-ui/core/styles';
 import { OverridableComponent, OverrideProps } from '../OverridableComponent';
 
 export interface BreadcrumbsTypeMap<P = {}, D extends React.ElementType = 'nav'> {
@@ -49,6 +51,10 @@ export interface BreadcrumbsTypeMap<P = {}, D extends React.ElementType = 'nav'>
      * @default '/'
      */
     separator?: React.ReactNode;
+    /**
+     * The system prop that allows defining system overrides as well as additional CSS styles.
+     */
+    sx?: SxProps<Theme>;
   };
   defaultComponent: D;
 }
diff --git a/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js b/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js
index a18f02e091569e..9991ac2fa51bad 100644
--- a/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js
+++ b/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js
@@ -2,41 +2,88 @@ import * as React from 'react';
 import { isFragment } from 'react-is';
 import PropTypes from 'prop-types';
 import clsx from 'clsx';
-import withStyles from '../styles/withStyles';
+import { deepmerge } from '@material-ui/utils';
+import { unstable_composeClasses as composeClasses } from '@material-ui/unstyled';
+import experimentalStyled from '../styles/experimentalStyled';
+import useThemeProps from '../styles/useThemeProps';
 import Typography from '../Typography';
 import BreadcrumbCollapsed from './BreadcrumbCollapsed';
+import breadcrumbsClasses, { getBreadcrumbsUtilityClass } from './breadcrumbsClasses';
 
-export const styles = {
-  /* Styles applied to the root element. */
-  root: {},
-  /* Styles applied to the ol element. */
-  ol: {
-    display: 'flex',
-    flexWrap: 'wrap',
-    alignItems: 'center',
-    padding: 0,
-    margin: 0,
-    listStyle: 'none',
+const overridesResolver = (props, styles) => {
+  return deepmerge(styles.root || {}, {
+    [`& .${breadcrumbsClasses.ol}`]: styles.ol,
+    [`& .${breadcrumbsClasses.li}`]: styles.li,
+    [`& .${breadcrumbsClasses.separator}`]: styles.separator,
+  });
+};
+
+const useUtilityClasses = (styleProps) => {
+  const { classes } = styleProps;
+
+  const slots = {
+    root: ['root'],
+    li: ['li'],
+    ol: ['ol'],
+    separator: ['separator'],
+  };
+
+  return composeClasses(slots, getBreadcrumbsUtilityClass, classes);
+};
+
+const BreadcrumbsRoot = experimentalStyled(
+  Typography,
+  {},
+  {
+    name: 'MuiBreadcrumbs',
+    slot: 'Root',
+    overridesResolver,
   },
-  /* Styles applied to the li element. */
-  li: {},
-  /* Styles applied to the separator element. */
-  separator: {
-    display: 'flex',
-    userSelect: 'none',
-    marginLeft: 8,
-    marginRight: 8,
+)({});
+
+const BreadcrumbsOl = experimentalStyled(
+  'ol',
+  {},
+  {
+    name: 'MuiBreadcrumbs',
+    slot: 'Ol',
   },
-};
+)({
+  display: 'flex',
+  flexWrap: 'wrap',
+  alignItems: 'center',
+  padding: 0,
+  margin: 0,
+  listStyle: 'none',
+});
 
-function insertSeparators(items, className, separator) {
+const BreadcrumbsSeparator = experimentalStyled(
+  'li',
+  {},
+  {
+    name: 'MuiBreadcrumbs',
+    slot: 'Separator',
+  },
+)({
+  display: 'flex',
+  userSelect: 'none',
+  marginLeft: 8,
+  marginRight: 8,
+});
+
+function insertSeparators(items, className, separator, styleProps) {
   return items.reduce((acc, current, index) => {
     if (index < items.length - 1) {
       acc = acc.concat(
         current,
-        <li aria-hidden key={`separator-${index}`} className={className}>
+        <BreadcrumbsSeparator
+          aria-hidden
+          key={`separator-${index}`}
+          className={className}
+          styleProps={styleProps}
+        >
           {separator}
-        </li>,
+        </BreadcrumbsSeparator>,
       );
     } else {
       acc.push(current);
@@ -46,12 +93,12 @@ function insertSeparators(items, className, separator) {
   }, []);
 }
 
-const Breadcrumbs = React.forwardRef(function Breadcrumbs(props, ref) {
+const Breadcrumbs = React.forwardRef(function Breadcrumbs(inProps, ref) {
+  const props = useThemeProps({ props: inProps, name: 'MuiBreadcrumbs' });
   const {
     children,
-    classes,
     className,
-    component: Component = 'nav',
+    component = 'nav',
     expandText = 'Show path',
     itemsAfterCollapse = 1,
     itemsBeforeCollapse = 1,
@@ -62,6 +109,19 @@ const Breadcrumbs = React.forwardRef(function Breadcrumbs(props, ref) {
 
   const [expanded, setExpanded] = React.useState(false);
 
+  const styleProps = {
+    ...props,
+    component,
+    expanded,
+    expandText,
+    itemsAfterCollapse,
+    itemsBeforeCollapse,
+    maxItems,
+    separator,
+  };
+
+  const classes = useUtilityClasses(styleProps);
+
   const listRef = React.useRef(null);
   const renderItemsBeforeAndAfter = (allItems) => {
     const handleClickExpand = () => {
@@ -120,23 +180,25 @@ const Breadcrumbs = React.forwardRef(function Breadcrumbs(props, ref) {
     ));
 
   return (
-    <Typography
+    <BreadcrumbsRoot
       ref={ref}
-      component={Component}
+      component={component}
       color="textSecondary"
       className={clsx(classes.root, className)}
+      styleProps={styleProps}
       {...other}
     >
-      <ol className={classes.ol} ref={listRef}>
+      <BreadcrumbsOl className={classes.ol} ref={listRef} styleProps={styleProps}>
         {insertSeparators(
           expanded || (maxItems && allItems.length <= maxItems)
             ? allItems
             : renderItemsBeforeAndAfter(allItems),
           classes.separator,
           separator,
+          styleProps,
         )}
-      </ol>
-    </Typography>
+      </BreadcrumbsOl>
+    </BreadcrumbsRoot>
   );
 });
 
@@ -191,6 +253,10 @@ Breadcrumbs.propTypes = {
    * @default '/'
    */
   separator: PropTypes.node,
+  /**
+   * The system prop that allows defining system overrides as well as additional CSS styles.
+   */
+  sx: PropTypes.object,
 };
 
-export default withStyles(styles, { name: 'MuiBreadcrumbs' })(Breadcrumbs);
+export default Breadcrumbs;
diff --git a/packages/material-ui/src/Breadcrumbs/Breadcrumbs.test.js b/packages/material-ui/src/Breadcrumbs/Breadcrumbs.test.js
index 6403c057b898ab..acf662d0d9ae9f 100644
--- a/packages/material-ui/src/Breadcrumbs/Breadcrumbs.test.js
+++ b/packages/material-ui/src/Breadcrumbs/Breadcrumbs.test.js
@@ -1,34 +1,22 @@
 import * as React from 'react';
 import { expect } from 'chai';
-import {
-  getClasses,
-  createMount,
-  describeConformance,
-  act,
-  createClientRender,
-  screen,
-} from 'test/utils';
+import { createMount, describeConformanceV5, act, createClientRender, screen } from 'test/utils';
 import Breadcrumbs from './Breadcrumbs';
+import classes from './breadcrumbsClasses';
 
 describe('<Breadcrumbs />', () => {
   const mount = createMount();
-  let classes;
   const render = createClientRender();
 
-  before(() => {
-    classes = getClasses(
-      <Breadcrumbs>
-        <span>Hello World</span>
-      </Breadcrumbs>,
-    );
-  });
-
-  describeConformance(<Breadcrumbs>Conformance?</Breadcrumbs>, () => ({
+  describeConformanceV5(<Breadcrumbs>Conformance?</Breadcrumbs>, () => ({
     classes,
     inheritComponent: 'nav',
     mount,
+    muiName: 'MuiBreadcrumbs',
     refInstanceof: window.HTMLElement,
     testComponentPropWith: 'div',
+    testVariantProps: { separator: '=' },
+    skip: ['componentsProp'],
   }));
 
   it('should render inaccessible separators between each listitem', () => {
diff --git a/packages/material-ui/src/Breadcrumbs/breadcrumbCollapsedClasses.d.ts b/packages/material-ui/src/Breadcrumbs/breadcrumbCollapsedClasses.d.ts
new file mode 100644
index 00000000000000..dfa4ccbb35dd6c
--- /dev/null
+++ b/packages/material-ui/src/Breadcrumbs/breadcrumbCollapsedClasses.d.ts
@@ -0,0 +1,10 @@
+export interface BreadcrumbCollapsedClasses {
+  button: string;
+  icon: string;
+}
+
+declare const breadcrumbCollapsedClasses: BreadcrumbCollapsedClasses;
+
+export function getBreadcrumbCollapsedUtilityClass(slot: string): string;
+
+export default breadcrumbCollapsedClasses;
diff --git a/packages/material-ui/src/Breadcrumbs/breadcrumbCollapsedClasses.js b/packages/material-ui/src/Breadcrumbs/breadcrumbCollapsedClasses.js
new file mode 100644
index 00000000000000..59c70590090fd2
--- /dev/null
+++ b/packages/material-ui/src/Breadcrumbs/breadcrumbCollapsedClasses.js
@@ -0,0 +1,12 @@
+import { generateUtilityClass, generateUtilityClasses } from '@material-ui/unstyled';
+
+export function getBreadcrumbCollapsedUtilityClass(slot) {
+  return generateUtilityClass('PrivateBreadcrumbCollapsed', slot);
+}
+
+const breadcrumbCollapsedClasses = generateUtilityClasses('PrivateBreadcrumbCollapsed', [
+  'button',
+  'icon',
+]);
+
+export default breadcrumbCollapsedClasses;
diff --git a/packages/material-ui/src/Breadcrumbs/breadcrumbsClasses.d.ts b/packages/material-ui/src/Breadcrumbs/breadcrumbsClasses.d.ts
new file mode 100644
index 00000000000000..db9038f12b0f70
--- /dev/null
+++ b/packages/material-ui/src/Breadcrumbs/breadcrumbsClasses.d.ts
@@ -0,0 +1,12 @@
+export interface BreadcrumbsClasses {
+  root: string;
+  ol: string;
+  li: string;
+  separator: string;
+}
+
+declare const breadcrumbsClasses: BreadcrumbsClasses;
+
+export function getBreadcrumbsUtilityClass(slot: string): string;
+
+export default breadcrumbsClasses;
diff --git a/packages/material-ui/src/Breadcrumbs/breadcrumbsClasses.js b/packages/material-ui/src/Breadcrumbs/breadcrumbsClasses.js
new file mode 100644
index 00000000000000..c21d6bc1ea3539
--- /dev/null
+++ b/packages/material-ui/src/Breadcrumbs/breadcrumbsClasses.js
@@ -0,0 +1,14 @@
+import { generateUtilityClass, generateUtilityClasses } from '@material-ui/unstyled';
+
+export function getBreadcrumbsUtilityClass(slot) {
+  return generateUtilityClass('MuiBreadcrumbs', slot);
+}
+
+const breadcrumbsClasses = generateUtilityClasses('MuiBreadcrumbs', [
+  'root',
+  'ol',
+  'li',
+  'separator',
+]);
+
+export default breadcrumbsClasses;
diff --git a/packages/material-ui/src/Breadcrumbs/index.d.ts b/packages/material-ui/src/Breadcrumbs/index.d.ts
index d447c988bbcb58..fa0714c18f5187 100644
--- a/packages/material-ui/src/Breadcrumbs/index.d.ts
+++ b/packages/material-ui/src/Breadcrumbs/index.d.ts
@@ -1,2 +1,5 @@
 export { default } from './Breadcrumbs';
 export * from './Breadcrumbs';
+
+export { default as breadcrumbsClasses } from './breadcrumbsClasses';
+export * from './breadcrumbsClasses';
diff --git a/packages/material-ui/src/Breadcrumbs/index.js b/packages/material-ui/src/Breadcrumbs/index.js
index 3ff68ca58940e5..77829cbf764cab 100644
--- a/packages/material-ui/src/Breadcrumbs/index.js
+++ b/packages/material-ui/src/Breadcrumbs/index.js
@@ -1 +1,4 @@
 export { default } from './Breadcrumbs';
+
+export { default as breadcrumbsClasses } from './breadcrumbsClasses';
+export * from './breadcrumbsClasses';