diff --git a/.changeset/eleven-hounds-invent.md b/.changeset/eleven-hounds-invent.md
new file mode 100644
index 0000000000..ba863ebc28
--- /dev/null
+++ b/.changeset/eleven-hounds-invent.md
@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+In frontend builds and tests `process.env.HAS_REACT_DOM_CLIENT` will now be defined if `react-dom/client` is present, i.e. if using React 18. This allows for conditional imports of `react-dom/client`.
diff --git a/.changeset/shaggy-beers-collect.md b/.changeset/shaggy-beers-collect.md
new file mode 100644
index 0000000000..471368d6f2
--- /dev/null
+++ b/.changeset/shaggy-beers-collect.md
@@ -0,0 +1,6 @@
+---
+'@backstage/dev-utils': patch
+'@backstage/plugin-techdocs': patch
+---
+
+Added support for React 18. The new `createRoot` API from `react-dom/client` will now be used if present.
diff --git a/packages/dev-utils/src/devApp/render.tsx b/packages/dev-utils/src/devApp/render.tsx
index 335308ff5e..e45ba649f9 100644
--- a/packages/dev-utils/src/devApp/render.tsx
+++ b/packages/dev-utils/src/devApp/render.tsx
@@ -49,10 +49,7 @@ import { createRoutesFromChildren, Route } from 'react-router-dom';
 import { SidebarThemeSwitcher } from './SidebarThemeSwitcher';
 import 'react-dom';
 
-let ReactDOM:
-  | typeof import('react-dom')
-  // TODO: replace with import('react-dom/client') when repo is migrated to 18
-  | { createRoot(el: HTMLElement): { render(el: JSX.Element): void } };
+let ReactDOM: typeof import('react-dom') | typeof import('react-dom/client');
 if (process.env.HAS_REACT_DOM_CLIENT) {
   ReactDOM = require('react-dom/client');
 } else {
diff --git a/plugins/techdocs/src/reader/transformers/renderReactElement.ts b/plugins/techdocs/src/reader/transformers/renderReactElement.ts
index 86d44532c5..f9b45065f1 100644
--- a/plugins/techdocs/src/reader/transformers/renderReactElement.ts
+++ b/plugins/techdocs/src/reader/transformers/renderReactElement.ts
@@ -14,10 +14,7 @@
  * limitations under the License.
  */
 
-let ReactDOM:
-  | typeof import('react-dom')
-  // TODO: replace with import('react-dom/client') when repo is migrated to 18
-  | { createRoot(el: HTMLElement): { render(el: JSX.Element): void } };
+let ReactDOM: typeof import('react-dom') | typeof import('react-dom/client');
 if (process.env.HAS_REACT_DOM_CLIENT) {
   ReactDOM = require('react-dom/client');
 } else {