diff --git a/extensions/vscode-notebook-tests/src/notebook.test.ts b/extensions/vscode-notebook-tests/src/notebook.test.ts
index e3ea9eefece..238e7b2ecee 100644
--- a/extensions/vscode-notebook-tests/src/notebook.test.ts
+++ b/extensions/vscode-notebook-tests/src/notebook.test.ts
@@ -417,6 +417,37 @@ suite('Notebook API tests', () => {
 		await saveAllFilesAndCloseAll(resource);
 	});
 
+	test('edit API (replaceOutput, USE NotebookCellOutput-type)', async function () {
+		assertInitalState();
+		const resource = await createRandomFile('', undefined, 'first', '.vsctestnb');
+		await vscode.commands.executeCommand('vscode.openWith', resource, 'notebookCoreTest');
+
+		await vscode.notebook.activeNotebookEditor!.edit(editBuilder => {
+			editBuilder.replaceCellOutput(0, [
+				new vscode.NotebookCellOutput('application/foo', 'bar'),
+				new vscode.NotebookCellOutput('application/json', { data: true }, { metadata: true }),
+			]);
+		});
+
+		const document = vscode.notebook.activeNotebookEditor?.document!;
+		assert.strictEqual(document.isDirty, true);
+		assert.strictEqual(document.cells.length, 1);
+		assert.strictEqual(document.cells[0].outputs.length, 2);
+
+		// consuming is OLD api
+		const [one, two] = document.cells[0].outputs;
+
+		assert.strictEqual(one.outputKind, vscode.CellOutputKind.Rich);
+		assert.strictEqual((<vscode.CellDisplayOutput>one).data['application/foo'], 'bar');
+		assert.strictEqual((<vscode.CellDisplayOutput>one).metadata, undefined);
+
+		assert.strictEqual(two.outputKind, vscode.CellOutputKind.Rich);
+		assert.deepStrictEqual((<vscode.CellDisplayOutput>two).data['application/json'], { data: true });
+		assert.deepStrictEqual((<vscode.CellDisplayOutput>two).metadata, { custom: { metadata: true } });
+
+		await saveAllFilesAndCloseAll(undefined);
+	});
+
 	test('edit API (replaceOutput)', async function () {
 		assertInitalState();
 		const resource = await createRandomFile('', undefined, 'first', '.vsctestnb');
diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index ae1b9cd29ed..99d0458aacc 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -1237,6 +1237,15 @@ declare module 'vscode' {
 
 	export type CellOutput = CellStreamOutput | CellErrorOutput | CellDisplayOutput;
 
+	export class NotebookCellOutput {
+
+		readonly mime: string;
+		readonly value: unknown;
+		readonly metadata?: Record<string, string | number | boolean>;
+
+		constructor(mime: string, value: unknown, metadata?: Record<string, string | number | boolean>);
+	}
+
 	export enum NotebookCellRunState {
 		Running = 1,
 		Idle = 2,
@@ -1425,7 +1434,7 @@ declare module 'vscode' {
 	export interface NotebookEditorEdit {
 		replaceMetadata(value: NotebookDocumentMetadata): void;
 		replaceCells(start: number, end: number, cells: NotebookCellData[]): void;
-		replaceCellOutput(index: number, outputs: CellOutput[]): void;
+		replaceCellOutput(index: number, outputs: (NotebookCellOutput | CellOutput)[]): void;
 		replaceCellMetadata(index: number, metadata: NotebookCellMetadata): void;
 	}
 
diff --git a/src/vs/workbench/api/common/extHost.api.impl.ts b/src/vs/workbench/api/common/extHost.api.impl.ts
index 000b8a27af5..c23a0b17dd3 100644
--- a/src/vs/workbench/api/common/extHost.api.impl.ts
+++ b/src/vs/workbench/api/common/extHost.api.impl.ts
@@ -1147,7 +1147,8 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			NotebookCellRunState: extHostTypes.NotebookCellRunState,
 			NotebookRunState: extHostTypes.NotebookRunState,
 			NotebookCellStatusBarAlignment: extHostTypes.NotebookCellStatusBarAlignment,
-			NotebookEditorRevealType: extHostTypes.NotebookEditorRevealType
+			NotebookEditorRevealType: extHostTypes.NotebookEditorRevealType,
+			NotebookCellOutput: extHostTypes.NotebookCellOutput,
 		};
 	};
 }
diff --git a/src/vs/workbench/api/common/extHostNotebookEditor.ts b/src/vs/workbench/api/common/extHostNotebookEditor.ts
index ea5ecb3512d..425a3e98602 100644
--- a/src/vs/workbench/api/common/extHostNotebookEditor.ts
+++ b/src/vs/workbench/api/common/extHostNotebookEditor.ts
@@ -7,6 +7,7 @@ import { readonly } from 'vs/base/common/errors';
 import { Emitter, Event } from 'vs/base/common/event';
 import { Disposable } from 'vs/base/common/lifecycle';
 import { MainThreadNotebookShape } from 'vs/workbench/api/common/extHost.protocol';
+import { NotebookCellOutput } from 'vs/workbench/api/common/extHostTypeConverters';
 import * as extHostTypes from 'vs/workbench/api/common/extHostTypes';
 import { addIdToOutput, CellEditType, ICellEditOperation, ICellReplaceEdit, INotebookEditData, notebookDocumentMetadataDefaults } from 'vs/workbench/contrib/notebook/common/notebookCommon';
 import * as vscode from 'vscode';
@@ -54,12 +55,18 @@ class NotebookEditorCellEditBuilder implements vscode.NotebookEditorEdit {
 		});
 	}
 
-	replaceCellOutput(index: number, outputs: vscode.CellOutput[]): void {
+	replaceCellOutput(index: number, outputs: (vscode.NotebookCellOutput | vscode.CellOutput)[]): void {
 		this._throwIfFinalized();
 		this._collectedEdits.push({
 			editType: CellEditType.Output,
 			index,
-			outputs: outputs.map(output => addIdToOutput(output))
+			outputs: outputs.map(output => {
+				if (extHostTypes.NotebookCellOutput.isNotebookCellOutput(output)) {
+					return addIdToOutput(NotebookCellOutput.from(output));
+				} else {
+					return addIdToOutput(output);
+				}
+			})
 		});
 	}
 
diff --git a/src/vs/workbench/api/common/extHostTypeConverters.ts b/src/vs/workbench/api/common/extHostTypeConverters.ts
index f10f2fa7b89..9dab2c179b4 100644
--- a/src/vs/workbench/api/common/extHostTypeConverters.ts
+++ b/src/vs/workbench/api/common/extHostTypeConverters.ts
@@ -32,7 +32,7 @@ import { coalesce, isNonEmptyArray } from 'vs/base/common/arrays';
 import { RenderLineNumbersType } from 'vs/editor/common/config/editorOptions';
 import { CommandsConverter } from 'vs/workbench/api/common/extHostCommands';
 import { ExtHostNotebookController } from 'vs/workbench/api/common/extHostNotebook';
-import { INotebookDecorationRenderOptions } from 'vs/workbench/contrib/notebook/common/notebookCommon';
+import { CellOutputKind, IDisplayOutput, INotebookDecorationRenderOptions } from 'vs/workbench/contrib/notebook/common/notebookCommon';
 
 export interface PositionLike {
 	line: number;
@@ -1295,6 +1295,16 @@ export namespace LogLevel {
 	}
 }
 
+export namespace NotebookCellOutput {
+	export function from(output: types.NotebookCellOutput): IDisplayOutput {
+		return {
+			outputKind: CellOutputKind.Rich,
+			data: { [output.mime]: output.value },
+			metadata: output.metadata && { custom: output.metadata }
+		};
+	}
+}
+
 export namespace NotebookExclusiveDocumentPattern {
 	export function from(pattern: { include: vscode.GlobPattern | undefined, exclude: vscode.GlobPattern | undefined }): { include: string | types.RelativePattern | undefined, exclude: string | types.RelativePattern | undefined };
 	export function from(pattern: vscode.GlobPattern): string | types.RelativePattern;
diff --git a/src/vs/workbench/api/common/extHostTypes.ts b/src/vs/workbench/api/common/extHostTypes.ts
index 1497c19da9c..99ab95e9e81 100644
--- a/src/vs/workbench/api/common/extHostTypes.ts
+++ b/src/vs/workbench/api/common/extHostTypes.ts
@@ -2765,6 +2765,19 @@ export enum ColorThemeKind {
 
 //#region Notebook
 
+export class NotebookCellOutput {
+
+	static isNotebookCellOutput(obj: unknown): obj is vscode.NotebookCellOutput {
+		return obj instanceof NotebookCellOutput;
+	}
+
+	constructor(
+		readonly mime: string,
+		readonly value: unknown, // JSON'able
+		readonly metadata?: Record<string, string | number | boolean>
+	) { }
+}
+
 export enum CellKind {
 	Markdown = 1,
 	Code = 2