diff --git a/src/vs/editor/browser/viewParts/lineNumbers/lineNumbers.ts b/src/vs/editor/browser/viewParts/lineNumbers/lineNumbers.ts
index 92537ee51db..03336d34278 100644
--- a/src/vs/editor/browser/viewParts/lineNumbers/lineNumbers.ts
+++ b/src/vs/editor/browser/viewParts/lineNumbers/lineNumbers.ts
@@ -8,6 +8,7 @@ import * as platform from 'vs/base/common/platform';
 import { DynamicViewOverlay } from 'vs/editor/browser/view/dynamicViewOverlay';
 import { RenderLineNumbersType, EditorOption } from 'vs/editor/common/config/editorOptions';
 import { Position } from 'vs/editor/common/core/position';
+import { Range } from 'vs/editor/common/core/range';
 import { RenderingContext } from 'vs/editor/browser/view/renderingContext';
 import { ViewContext } from 'vs/editor/common/viewModel/viewContext';
 import * as viewEvents from 'vs/editor/common/viewEvents';
@@ -98,6 +99,9 @@ export class LineNumbersOverlay extends DynamicViewOverlay {
 	public override onZonesChanged(e: viewEvents.ViewZonesChangedEvent): boolean {
 		return true;
 	}
+	public override onDecorationsChanged(e: viewEvents.ViewDecorationsChangedEvent): boolean {
+		return e.affectsLineNumber;
+	}
 
 	// --- end event handlers
 
@@ -143,36 +147,50 @@ export class LineNumbersOverlay extends DynamicViewOverlay {
 		const visibleStartLineNumber = ctx.visibleRange.startLineNumber;
 		const visibleEndLineNumber = ctx.visibleRange.endLineNumber;
 
+		const lineNoDecorations = this._context.viewModel.getDecorationsInViewport(ctx.visibleRange).filter(d => !!d.options.lineNumberClassName);
+		lineNoDecorations.sort((a, b) => Range.compareRangesUsingEnds(a.range, b.range));
+		let decorationStartIndex = 0;
+
 		const lineCount = this._context.viewModel.getLineCount();
 		const output: string[] = [];
 		for (let lineNumber = visibleStartLineNumber; lineNumber <= visibleEndLineNumber; lineNumber++) {
 			const lineIndex = lineNumber - visibleStartLineNumber;
 
-			const renderLineNumber = this._getLineRenderLineNumber(lineNumber);
+			let renderLineNumber = this._getLineRenderLineNumber(lineNumber);
+			let extraClassNames = '';
 
-			if (!renderLineNumber) {
+			// skip decorations whose end positions we've already passed
+			while (decorationStartIndex < lineNoDecorations.length && lineNoDecorations[decorationStartIndex].range.endLineNumber < lineNumber) {
+				decorationStartIndex++;
+			}
+			for (let i = decorationStartIndex; i < lineNoDecorations.length; i++) {
+				const { range, options } = lineNoDecorations[i];
+				if (range.startLineNumber <= lineNumber) {
+					extraClassNames += ' ' + options.lineNumberClassName;
+				}
+			}
+
+			if (!renderLineNumber && !extraClassNames) {
 				output[lineIndex] = '';
 				continue;
 			}
 
-			let extraClassName = '';
-
 			if (lineNumber === lineCount && this._context.viewModel.getLineLength(lineNumber) === 0) {
 				// this is the last line
 				if (this._renderFinalNewline === 'off') {
-					output[lineIndex] = '';
-					continue;
+					renderLineNumber = '';
 				}
 				if (this._renderFinalNewline === 'dimmed') {
-					extraClassName = ' dimmed-line-number';
+					extraClassNames += ' dimmed-line-number';
 				}
 			}
 			if (lineNumber === this._activeLineNumber) {
-				extraClassName = ' active-line-number';
+				extraClassNames += ' active-line-number';
 			}
 
+
 			output[lineIndex] = (
-				`<div class="${LineNumbersOverlay.CLASS_NAME}${lineHeightClassName}${extraClassName}" style="left:${this._lineNumbersLeft}px;width:${this._lineNumbersWidth}px;">${renderLineNumber}</div>`
+				`<div class="${LineNumbersOverlay.CLASS_NAME}${lineHeightClassName}${extraClassNames}" style="left:${this._lineNumbersLeft}px;width:${this._lineNumbersWidth}px;">${renderLineNumber}</div>`
 			);
 		}
 
diff --git a/src/vs/editor/common/model.ts b/src/vs/editor/common/model.ts
index 3d84860632f..ad0d31765ff 100644
--- a/src/vs/editor/common/model.ts
+++ b/src/vs/editor/common/model.ts
@@ -160,6 +160,10 @@ export interface IModelDecorationOptions {
 	 * Array of MarkdownString to render as the decoration message.
 	 */
 	hoverMessage?: IMarkdownString | IMarkdownString[] | null;
+	/**
+	 * Array of MarkdownString to render as the line number message.
+	 */
+	lineNumberHoverMessage?: IMarkdownString | IMarkdownString[] | null;
 	/**
 	 * Should the decoration expand to encompass a whole line.
 	 */
@@ -204,6 +208,10 @@ export interface IModelDecorationOptions {
 	 * Controls the tooltip text of the line decoration.
 	 */
 	linesDecorationsTooltip?: string | null;
+	/**
+	 * If set, the decoration will be rendered on the line number.
+	 */
+	lineNumberClassName?: string | null;
 	/**
 	 * If set, the decoration will be rendered in the lines decorations with this CSS class name, but only for the first line in case of line wrapping.
 	 */
diff --git a/src/vs/editor/common/model/textModel.ts b/src/vs/editor/common/model/textModel.ts
index 8b91f6ae75e..e3e8239cb55 100644
--- a/src/vs/editor/common/model/textModel.ts
+++ b/src/vs/editor/common/model/textModel.ts
@@ -2299,6 +2299,8 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 	readonly glyphMargin?: model.IModelDecorationGlyphMarginOptions | null | undefined;
 	readonly glyphMarginClassName: string | null;
 	readonly linesDecorationsClassName: string | null;
+	readonly lineNumberClassName: string | null;
+	readonly lineNumberHoverMessage: IMarkdownString | IMarkdownString[] | null;
 	readonly linesDecorationsTooltip: string | null;
 	readonly firstLineDecorationClassName: string | null;
 	readonly marginClassName: string | null;
@@ -2323,6 +2325,7 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 		this.shouldFillLineOnLineBreak = options.shouldFillLineOnLineBreak ?? null;
 		this.hoverMessage = options.hoverMessage || null;
 		this.glyphMarginHoverMessage = options.glyphMarginHoverMessage || null;
+		this.lineNumberHoverMessage = options.lineNumberHoverMessage || null;
 		this.isWholeLine = options.isWholeLine || false;
 		this.showIfCollapsed = options.showIfCollapsed || false;
 		this.collapseOnReplaceEdit = options.collapseOnReplaceEdit || false;
@@ -2331,6 +2334,7 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 		this.glyphMargin = options.glyphMarginClassName ? new ModelDecorationGlyphMarginOptions(options.glyphMargin) : null;
 		this.glyphMarginClassName = options.glyphMarginClassName ? cleanClassName(options.glyphMarginClassName) : null;
 		this.linesDecorationsClassName = options.linesDecorationsClassName ? cleanClassName(options.linesDecorationsClassName) : null;
+		this.lineNumberClassName = options.lineNumberClassName ? cleanClassName(options.lineNumberClassName) : null;
 		this.linesDecorationsTooltip = options.linesDecorationsTooltip ? strings.htmlAttributeEncodeValue(options.linesDecorationsTooltip) : null;
 		this.firstLineDecorationClassName = options.firstLineDecorationClassName ? cleanClassName(options.firstLineDecorationClassName) : null;
 		this.marginClassName = options.marginClassName ? cleanClassName(options.marginClassName) : null;
@@ -2374,6 +2378,7 @@ class DidChangeDecorationsEmitter extends Disposable {
 	private _affectsOverviewRuler: boolean;
 	private _affectedInjectedTextLines: Set<number> | null = null;
 	private _affectsGlyphMargin: boolean;
+	private _affectsLineNumber: boolean;
 
 	constructor(private readonly handleBeforeFire: (affectedInjectedTextLines: Set<number> | null) => void) {
 		super();
@@ -2382,6 +2387,7 @@ class DidChangeDecorationsEmitter extends Disposable {
 		this._affectsMinimap = false;
 		this._affectsOverviewRuler = false;
 		this._affectsGlyphMargin = false;
+		this._affectsLineNumber = false;
 	}
 
 	hasListeners(): boolean {
@@ -2412,15 +2418,10 @@ class DidChangeDecorationsEmitter extends Disposable {
 	}
 
 	public checkAffectedAndFire(options: ModelDecorationOptions): void {
-		if (!this._affectsMinimap) {
-			this._affectsMinimap = options.minimap && options.minimap.position ? true : false;
-		}
-		if (!this._affectsOverviewRuler) {
-			this._affectsOverviewRuler = options.overviewRuler && options.overviewRuler.color ? true : false;
-		}
-		if (!this._affectsGlyphMargin) {
-			this._affectsGlyphMargin = options.glyphMarginClassName ? true : false;
-		}
+		this._affectsMinimap ||= !!options.minimap?.position;
+		this._affectsOverviewRuler ||= !!options.overviewRuler?.color;
+		this._affectsGlyphMargin ||= !!options.glyphMarginClassName;
+		this._affectsLineNumber ||= !!options.lineNumberClassName;
 		this.tryFire();
 	}
 
@@ -2445,7 +2446,8 @@ class DidChangeDecorationsEmitter extends Disposable {
 		const event: IModelDecorationsChangedEvent = {
 			affectsMinimap: this._affectsMinimap,
 			affectsOverviewRuler: this._affectsOverviewRuler,
-			affectsGlyphMargin: this._affectsGlyphMargin
+			affectsGlyphMargin: this._affectsGlyphMargin,
+			affectsLineNumber: this._affectsLineNumber,
 		};
 		this._shouldFireDeferred = false;
 		this._affectsMinimap = false;
diff --git a/src/vs/editor/common/textModelEvents.ts b/src/vs/editor/common/textModelEvents.ts
index 8c25e06776d..58c720ac87c 100644
--- a/src/vs/editor/common/textModelEvents.ts
+++ b/src/vs/editor/common/textModelEvents.ts
@@ -91,6 +91,7 @@ export interface IModelDecorationsChangedEvent {
 	readonly affectsMinimap: boolean;
 	readonly affectsOverviewRuler: boolean;
 	readonly affectsGlyphMargin: boolean;
+	readonly affectsLineNumber: boolean;
 }
 
 /**
diff --git a/src/vs/editor/common/viewEvents.ts b/src/vs/editor/common/viewEvents.ts
index 0e6cb0fa166..f607afe73e9 100644
--- a/src/vs/editor/common/viewEvents.ts
+++ b/src/vs/editor/common/viewEvents.ts
@@ -76,16 +76,19 @@ export class ViewDecorationsChangedEvent {
 	readonly affectsMinimap: boolean;
 	readonly affectsOverviewRuler: boolean;
 	readonly affectsGlyphMargin: boolean;
+	readonly affectsLineNumber: boolean;
 
 	constructor(source: IModelDecorationsChangedEvent | null) {
 		if (source) {
 			this.affectsMinimap = source.affectsMinimap;
 			this.affectsOverviewRuler = source.affectsOverviewRuler;
 			this.affectsGlyphMargin = source.affectsGlyphMargin;
+			this.affectsLineNumber = source.affectsLineNumber;
 		} else {
 			this.affectsMinimap = true;
 			this.affectsOverviewRuler = true;
 			this.affectsGlyphMargin = true;
+			this.affectsLineNumber = true;
 		}
 	}
 }
diff --git a/src/vs/editor/contrib/hover/browser/hover.ts b/src/vs/editor/contrib/hover/browser/hover.ts
index 08b2a7bb68d..509eb67e324 100644
--- a/src/vs/editor/contrib/hover/browser/hover.ts
+++ b/src/vs/editor/contrib/hover/browser/hover.ts
@@ -300,6 +300,12 @@ export class HoverController extends Disposable implements IEditorContribution {
 			glyphWidget.startShowingAt(target.position.lineNumber, target.detail.glyphMarginLane);
 			return;
 		}
+		if (target.type === MouseTargetType.GUTTER_LINE_NUMBERS && target.position) {
+			this._contentWidget?.hide();
+			const glyphWidget = this._getOrCreateGlyphWidget();
+			glyphWidget.startShowingAt(target.position.lineNumber, 'lineNo');
+			return;
+		}
 		if (_sticky) {
 			return;
 		}
diff --git a/src/vs/editor/contrib/hover/browser/marginHover.ts b/src/vs/editor/contrib/hover/browser/marginHover.ts
index 98af0a06cda..e9eb33604c1 100644
--- a/src/vs/editor/contrib/hover/browser/marginHover.ts
+++ b/src/vs/editor/contrib/hover/browser/marginHover.ts
@@ -22,6 +22,8 @@ export interface IHoverMessage {
 	value: IMarkdownString;
 }
 
+type LaneOrLineNumber = GlyphMarginLane | 'lineNo';
+
 export class MarginHoverWidget extends Disposable implements IOverlayWidget {
 
 	public static readonly ID = 'editor.contrib.modesGlyphHoverWidget';
@@ -99,8 +101,8 @@ export class MarginHoverWidget extends Disposable implements IOverlayWidget {
 		}
 	}
 
-	public startShowingAt(lineNumber: number, lane: GlyphMarginLane): void {
-		if (this._computer.lineNumber === lineNumber && this._computer.lane === lane) {
+	public startShowingAt(lineNumber: number, laneOrLine: LaneOrLineNumber): void {
+		if (this._computer.lineNumber === lineNumber && this._computer.lane === laneOrLine) {
 			// We have to show the widget at the exact same line number as before, so no work is needed
 			return;
 		}
@@ -110,7 +112,7 @@ export class MarginHoverWidget extends Disposable implements IOverlayWidget {
 		this.hide();
 
 		this._computer.lineNumber = lineNumber;
-		this._computer.lane = lane;
+		this._computer.lane = laneOrLine;
 		this._hoverOperation.start(HoverStartMode.Delayed);
 	}
 
@@ -169,8 +171,8 @@ export class MarginHoverWidget extends Disposable implements IOverlayWidget {
 		const lineHeight = this._editor.getOption(EditorOption.lineHeight);
 		const nodeHeight = this._hover.containerDomNode.clientHeight;
 		const top = topForLineNumber - editorScrollTop - ((nodeHeight - lineHeight) / 2);
-
-		this._hover.containerDomNode.style.left = `${editorLayout.glyphMarginLeft + editorLayout.glyphMarginWidth}px`;
+		const left = editorLayout.glyphMarginLeft + editorLayout.glyphMarginWidth + (this._computer.lane === 'lineNo' ? editorLayout.lineNumbersWidth : 0);
+		this._hover.containerDomNode.style.left = `${left}px`;
 		this._hover.containerDomNode.style.top = `${Math.max(Math.round(top), 0)}px`;
 	}
 }
@@ -178,7 +180,7 @@ export class MarginHoverWidget extends Disposable implements IOverlayWidget {
 class MarginHoverComputer implements IHoverComputer<IHoverMessage> {
 
 	private _lineNumber: number = -1;
-	private _lane = GlyphMarginLane.Center;
+	private _laneOrLine: LaneOrLineNumber = GlyphMarginLane.Center;
 
 	public get lineNumber(): number {
 		return this._lineNumber;
@@ -188,12 +190,12 @@ class MarginHoverComputer implements IHoverComputer<IHoverMessage> {
 		this._lineNumber = value;
 	}
 
-	public get lane(): number {
-		return this._lane;
+	public get lane(): LaneOrLineNumber {
+		return this._laneOrLine;
 	}
 
-	public set lane(value: GlyphMarginLane) {
-		this._lane = value;
+	public set lane(value: LaneOrLineNumber) {
+		this._laneOrLine = value;
 	}
 
 	constructor(
@@ -212,21 +214,18 @@ class MarginHoverComputer implements IHoverComputer<IHoverMessage> {
 		const lineDecorations = this._editor.getLineDecorations(this._lineNumber);
 
 		const result: IHoverMessage[] = [];
+		const isLineHover = this._laneOrLine === 'lineNo';
 		if (!lineDecorations) {
 			return result;
 		}
 
 		for (const d of lineDecorations) {
-			if (!d.options.glyphMarginClassName) {
-				continue;
-			}
-
 			const lane = d.options.glyphMargin?.position ?? GlyphMarginLane.Center;
-			if (lane !== this._lane) {
+			if (!isLineHover && lane !== this._laneOrLine) {
 				continue;
 			}
 
-			const hoverMessage = d.options.glyphMarginHoverMessage;
+			const hoverMessage = isLineHover ? d.options.lineNumberHoverMessage : d.options.glyphMarginHoverMessage;
 			if (!hoverMessage || isEmptyMarkdownString(hoverMessage)) {
 				continue;
 			}
diff --git a/src/vs/monaco.d.ts b/src/vs/monaco.d.ts
index ac4a31bd48e..f0028ac35dc 100644
--- a/src/vs/monaco.d.ts
+++ b/src/vs/monaco.d.ts
@@ -1691,6 +1691,10 @@ declare namespace monaco.editor {
 		 * Array of MarkdownString to render as the decoration message.
 		 */
 		hoverMessage?: IMarkdownString | IMarkdownString[] | null;
+		/**
+		 * Array of MarkdownString to render as the line number message.
+		 */
+		lineNumberHoverMessage?: IMarkdownString | IMarkdownString[] | null;
 		/**
 		 * Should the decoration expand to encompass a whole line.
 		 */
@@ -1730,6 +1734,10 @@ declare namespace monaco.editor {
 		 * Controls the tooltip text of the line decoration.
 		 */
 		linesDecorationsTooltip?: string | null;
+		/**
+		 * If set, the decoration will be rendered on the line number.
+		 */
+		lineNumberClassName?: string | null;
 		/**
 		 * If set, the decoration will be rendered in the lines decorations with this CSS class name, but only for the first line in case of line wrapping.
 		 */
@@ -2930,6 +2938,7 @@ declare namespace monaco.editor {
 		readonly affectsMinimap: boolean;
 		readonly affectsOverviewRuler: boolean;
 		readonly affectsGlyphMargin: boolean;
+		readonly affectsLineNumber: boolean;
 	}
 
 	export interface IModelOptionsChangedEvent {
diff --git a/src/vs/workbench/contrib/testing/browser/codeCoverageDecorations.ts b/src/vs/workbench/contrib/testing/browser/codeCoverageDecorations.ts
index 856c7d4e6ae..7fb11557806 100644
--- a/src/vs/workbench/contrib/testing/browser/codeCoverageDecorations.ts
+++ b/src/vs/workbench/contrib/testing/browser/codeCoverageDecorations.ts
@@ -11,14 +11,13 @@ import { ICodeEditor, MouseTargetType } from 'vs/editor/browser/editorBrowser';
 import { Position } from 'vs/editor/common/core/position';
 import { Range } from 'vs/editor/common/core/range';
 import { IEditorContribution } from 'vs/editor/common/editorCommon';
-import { GlyphMarginLane, IModelDecorationOptions, ITextModel } from 'vs/editor/common/model';
+import { IModelDecorationOptions, ITextModel } from 'vs/editor/common/model';
 import { localize } from 'vs/nls';
 import { ILogService } from 'vs/platform/log/common/log';
 import { FileCoverage } from 'vs/workbench/contrib/testing/common/testCoverage';
 import { ITestCoverageService } from 'vs/workbench/contrib/testing/common/testCoverageService';
 import { CoverageDetails, DetailType, IStatementCoverage } from 'vs/workbench/contrib/testing/common/testTypes';
 
-const GLYPH_LANE = GlyphMarginLane.Left;
 const MAX_HOVERED_LINES = 30;
 const CLASS_HIT = 'coverage-deco-hit';
 const CLASS_MISS = 'coverage-deco-miss';
@@ -66,8 +65,7 @@ export class CodeCoverageDecorations extends Disposable implements IEditorContri
 		}));
 
 		this._register(editor.onMouseMove(e => {
-			if (e.target.type === MouseTargetType.GUTTER_GLYPH_MARGIN
-				&& e.target.detail.glyphMarginLane === GLYPH_LANE) {
+			if (e.target.type === MouseTargetType.GUTTER_LINE_NUMBERS) {
 				this.hoverLineNumber(editor.getModel()!, e.target.position.lineNumber);
 			} else {
 				this.hoveredStore.clear();
@@ -143,11 +141,10 @@ export class CodeCoverageDecorations extends Disposable implements IEditorContri
 					const opts: IModelDecorationOptions = {
 						showIfCollapsed: false,
 						description: 'coverage-gutter',
-						glyphMargin: { position: GlyphMarginLane.Left, persistLane: true },
-						glyphMarginHoverMessage: new MarkdownString()
+						lineNumberHoverMessage: new MarkdownString()
 							.appendCodeblock(model.getLanguageId(), model.getValueInRange(range))
 							.appendText(localize('testing.branchHitCount', 'Branch hit count: {0}', hits)),
-						glyphMarginClassName: `coverage-deco-gutter ${cls}`,
+						lineNumberClassName: `coverage-deco-gutter ${cls}`,
 					};
 
 					this.decorationIds.set(e.addDecoration(range, opts), {
@@ -161,11 +158,10 @@ export class CodeCoverageDecorations extends Disposable implements IEditorContri
 					const opts: IModelDecorationOptions = {
 						showIfCollapsed: false,
 						description: 'coverage-inline',
-						glyphMargin: { position: GlyphMarginLane.Left, persistLane: true },
-						glyphMarginHoverMessage: new MarkdownString()
+						lineNumberHoverMessage: new MarkdownString()
 							.appendCodeblock(model.getLanguageId(), model.getValueInRange(range))
 							.appendText(localize('testing.hitCount', 'Hit count: {0}', detail.count)),
-						glyphMarginClassName: `coverage-deco-gutter ${cls}`,
+						lineNumberClassName: `coverage-deco-gutter ${cls}`,
 					};
 
 					this.decorationIds.set(e.addDecoration(range, opts), {
diff --git a/src/vs/workbench/contrib/testing/browser/media/testing.css b/src/vs/workbench/contrib/testing/browser/media/testing.css
index 6168c064211..d40e482a1c7 100644
--- a/src/vs/workbench/contrib/testing/browser/media/testing.css
+++ b/src/vs/workbench/contrib/testing/browser/media/testing.css
@@ -417,12 +417,14 @@
 
 /** -- coverage decorations  */
 
+.coverage-deco-gutter {
+	z-index: 0;
+}
 .coverage-deco-gutter::before {
 	content: '';
 	position: absolute;
 	inset: 0;
-	right: 25%;
-	left: 25%;
+	z-index: -1;
 }
 
 .coverage-deco-gutter.coverage-deco-hit::before {