diff --git a/themebuilder/src/components/ThemeEditorToolbar.tsx b/themebuilder/src/components/ThemeEditorToolbar.tsx
index 29d049333344..40d55dc52899 100644
--- a/themebuilder/src/components/ThemeEditorToolbar.tsx
+++ b/themebuilder/src/components/ThemeEditorToolbar.tsx
@@ -3,7 +3,7 @@ import * as auth from "../services/authClient";
 import css from "./styling/ThemeEditor.module.scss";
 import { AppStateContext } from "../state/appStateContext";
 import { BaseThemePicker } from "./BaseThemePicker";
-import { exportTheme } from "../services/fileSystemService";
+import { exportTheme, importThemeFromFileAsync } from "../services/fileSystemService";
 import { Button } from "react-common/components/controls/Button";
 import { classList } from "react-common/components/util";
 import { ThemeManager } from "react-common/components/theming/themeManager";
@@ -21,6 +21,7 @@ export const ThemeEditorToolbar = () => {
         fgColor: "var(--pxt-neutral-foreground1)",
     };
     const { state } = React.useContext(AppStateContext);
+    const fileInputRef = React.useRef<HTMLInputElement>(null);
     const { editingTheme } = state;
     const [saveState, setSaveState] = React.useState<SaveState>(defaultSaveState);
 
@@ -36,6 +37,13 @@ export const ThemeEditorToolbar = () => {
         exportTheme(editingTheme);
     }
 
+    function handleImportFromFile(event: React.ChangeEvent<HTMLInputElement>) {
+        const file = event.target.files?.[0];
+        if (file) {
+            importThemeFromFileAsync(file);
+        }
+    }
+
     async function handleSaveToProfileClicked() {
         if (!editingTheme) return;
 
@@ -81,6 +89,21 @@ export const ThemeEditorToolbar = () => {
                     borderColor: saveState.fgColor,
                 }}
             />
+            {/* The button triggers a hidden file input to open the file browser */}
+            <Button
+                className={classList(css["import-button"], css["toolbar-icon-button"])}
+                title={lf("Import Theme From File")}
+                leftIcon="fas fa-file-import"
+                onClick={() => fileInputRef?.current?.click()}
+            />
+            <input
+                type="file"
+                ref={fileInputRef}
+                className="hidden"
+                onChange={handleImportFromFile}
+                aria-label={lf("Select Theme From File")}
+                accept=".json"
+            />
             <Button
                 className={classList(css["save-button"], css["toolbar-icon-button"])}
                 leftIcon="fas fa-file-export"
diff --git a/themebuilder/src/services/fileSystemService.ts b/themebuilder/src/services/fileSystemService.ts
index 68d87ea77e67..3cd2440846dd 100644
--- a/themebuilder/src/services/fileSystemService.ts
+++ b/themebuilder/src/services/fileSystemService.ts
@@ -1,4 +1,7 @@
 // Serializes the given theme and writes it to a file.
+
+import { setCurrentEditingTheme } from "../transforms/setCurrentEditingTheme";
+
 // Returns true if the file was written successfully, false otherwise.
 export function exportTheme(theme: pxt.ColorThemeInfo): boolean {
     if (!theme?.id) return false;
@@ -16,3 +19,15 @@ export function exportTheme(theme: pxt.ColorThemeInfo): boolean {
         return false;
     }
 }
+
+export async function importThemeFromFileAsync(file: File): Promise<boolean> {
+    try {
+        const themeJson = await pxt.Util.fileReadAsTextAsync(file);
+        const theme = JSON.parse(themeJson) as pxt.ColorThemeInfo;
+        setCurrentEditingTheme(theme);
+        return true;
+    } catch (error) {
+        console.error("Unable to parse theme.", error);
+        return false;
+    }
+}