diff --git a/ILSpy/App.axaml b/ILSpy/App.axaml
index 23c7988d0..4d50c7f1f 100644
--- a/ILSpy/App.axaml
+++ b/ILSpy/App.axaml
@@ -95,6 +95,7 @@
                     <SolidColorBrush x:Key="ILSpy.OmnibarBackground" Color="#F3F3F3" />
                     <SolidColorBrush x:Key="ILSpy.OmnibarBorder" Color="#FFC8CDD3" />
                     <SolidColorBrush x:Key="ILSpy.OmnibarHover" Color="#330078D7" />
+                    <SolidColorBrush x:Key="ILSpy.OmnibarScrollThumb" Color="#A6555555" />
                 </ResourceDictionary>
                 <ResourceDictionary x:Key="Dark">
                     <SolidColorBrush x:Key="ILSpy.EditorBackground" Color="#1E1E1E" />
@@ -152,6 +153,7 @@
                     <SolidColorBrush x:Key="ILSpy.OmnibarBackground" Color="#2D2D30" />
                     <SolidColorBrush x:Key="ILSpy.OmnibarBorder" Color="#3F3F46" />
                     <SolidColorBrush x:Key="ILSpy.OmnibarHover" Color="#330078D7" />
+                    <SolidColorBrush x:Key="ILSpy.OmnibarScrollThumb" Color="#A6C8C8C8" />
                 </ResourceDictionary>
             </ResourceDictionary.ThemeDictionaries>
 
diff --git a/ILSpy/Controls/Omnibar/Omnibar.axaml b/ILSpy/Controls/Omnibar/Omnibar.axaml
index 221e38527..47b47be9c 100644
--- a/ILSpy/Controls/Omnibar/Omnibar.axaml
+++ b/ILSpy/Controls/Omnibar/Omnibar.axaml
@@ -9,7 +9,57 @@
              x:DataType="omnibar:OmnibarViewModel"
              Name="self">
 
+	<UserControl.Resources>
+		<!-- Thin, button-less overlay scrollbar for the breadcrumb. The Simple theme's scrollbar
+		     reserves a layout row (shifting the crumbs) and never auto-hides, so the breadcrumb
+		     hides its built-in bar and overlays this one instead: a bare track + rounded thumb that
+		     fades in (see the fade style below) only while the path overflows and the pointer is
+		     over the bar. -->
+		<ControlTheme x:Key="OmnibarOverflowScrollBar" TargetType="ScrollBar">
+			<Setter Property="Height" Value="6" />
+			<Setter Property="MinHeight" Value="6" />
+			<Setter Property="Background" Value="Transparent" />
+			<Setter Property="Opacity" Value="0" />
+			<Setter Property="IsHitTestVisible" Value="False" />
+			<Setter Property="Transitions">
+				<Transitions>
+					<DoubleTransition Property="Opacity" Duration="0:0:0.15" />
+				</Transitions>
+			</Setter>
+			<Setter Property="Template">
+				<ControlTemplate>
+					<Border Background="Transparent" Padding="2,0,2,1">
+						<Track Name="PART_Track"
+						       Orientation="Horizontal"
+						       Minimum="{TemplateBinding Minimum}"
+						       Maximum="{TemplateBinding Maximum}"
+						       Value="{TemplateBinding Value, Mode=TwoWay}"
+						       ViewportSize="{TemplateBinding ViewportSize}">
+							<Track.Thumb>
+								<Thumb Height="4" MinWidth="24" VerticalAlignment="Center"
+								       Background="{DynamicResource ILSpy.OmnibarScrollThumb}">
+									<Thumb.Template>
+										<ControlTemplate>
+											<Border Background="{TemplateBinding Background}" CornerRadius="2" />
+										</ControlTemplate>
+									</Thumb.Template>
+								</Thumb>
+							</Track.Thumb>
+						</Track>
+					</Border>
+				</ControlTemplate>
+			</Setter>
+		</ControlTheme>
+	</UserControl.Resources>
+
 	<UserControl.Styles>
+		<!-- Reveal the overflow scrollbar (and make it grabbable) only while the pointer is over the
+		     breadcrumb; it fades back out on leave via the Opacity transition above. -->
+		<Style Selector="Grid#BreadcrumbFace:pointerover ScrollBar#BreadcrumbScrollbar">
+			<Setter Property="Opacity" Value="1" />
+			<Setter Property="IsHitTestVisible" Value="True" />
+		</Style>
+
 		<!-- Flat, transparent-until-hover treatment mirroring the toolbar buttons, so the bar
 		     reads as chrome rather than a row of raised buttons. -->
 		<Style Selector="Button.crumb">
@@ -54,11 +104,16 @@
 			<Panel>
 
 			<!-- Breadcrumb face: the trail plus a search affordance on the right. -->
-			<Grid ColumnDefinitions="*,Auto" IsVisible="{Binding IsBreadcrumbMode}">
-				<ScrollViewer Grid.Column="0"
-				              HorizontalScrollBarVisibility="Auto"
+			<Grid Name="BreadcrumbFace" ColumnDefinitions="*,Auto" IsVisible="{Binding IsBreadcrumbMode}">
+				<!-- The trail scrolls horizontally with its built-in bar hidden (the Simple theme's
+				     bar would reserve a row and shift the crumbs); a thin overlay bar is layered on
+				     top instead, and the mouse wheel scrolls the trail (see code-behind). -->
+				<Panel Grid.Column="0">
+				<ScrollViewer Name="BreadcrumbScroll"
+				              HorizontalScrollBarVisibility="Hidden"
 				              VerticalScrollBarVisibility="Disabled"
-				              VerticalAlignment="Center">
+				              VerticalAlignment="Center"
+				              PointerWheelChanged="OnBreadcrumbWheel">
 					<ItemsControl ItemsSource="{Binding Segments}">
 						<ItemsControl.ItemsPanel>
 							<ItemsPanelTemplate>
@@ -92,6 +147,16 @@
 						</ItemsControl.ItemTemplate>
 					</ItemsControl>
 				</ScrollViewer>
+				<ScrollBar Name="BreadcrumbScrollbar"
+				           Orientation="Horizontal"
+				           VerticalAlignment="Bottom"
+				           Theme="{StaticResource OmnibarOverflowScrollBar}"
+				           Minimum="0"
+				           Maximum="{Binding #BreadcrumbScroll.ScrollBarMaximum, Converter={x:Static omnibar:OmnibarScrollConverters.VectorX}}"
+				           ViewportSize="{Binding #BreadcrumbScroll.Viewport, Converter={x:Static omnibar:OmnibarScrollConverters.SizeWidth}}"
+				           Value="{Binding #BreadcrumbScroll.Offset, Mode=TwoWay, Converter={x:Static omnibar:OmnibarScrollConverters.VectorX}}"
+				           IsVisible="{Binding #BreadcrumbScroll.ScrollBarMaximum, Converter={x:Static omnibar:OmnibarScrollConverters.VectorXPositive}}" />
+				</Panel>
 				<Button Grid.Column="1" Classes="searchToggle" Click="OnEnterSearchClick"
 				        VerticalAlignment="Center"
 				        ToolTip.Tip="Search (Ctrl+L)">
diff --git a/ILSpy/Controls/Omnibar/Omnibar.axaml.cs b/ILSpy/Controls/Omnibar/Omnibar.axaml.cs
index 208d4c131..c194d05c4 100644
--- a/ILSpy/Controls/Omnibar/Omnibar.axaml.cs
+++ b/ILSpy/Controls/Omnibar/Omnibar.axaml.cs
@@ -98,6 +98,22 @@ namespace ICSharpCode.ILSpy.Controls.Omnibar
 		void OnEnterSearchClick(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
 			=> FocusSearch();
 
+		// Vertical scrolling is disabled on the breadcrumb, so the wheel is otherwise idle here;
+		// map it to horizontal scroll so the trail can be panned without hunting for the thin
+		// overlay thumb.
+		void OnBreadcrumbWheel(object? sender, PointerWheelEventArgs e)
+		{
+			var max = BreadcrumbScroll.ScrollBarMaximum.X;
+			if (max <= 0)
+				return;
+			// A wheel notch is one unit; crumbs are far wider, so scale up for a usable step.
+			const double step = 48;
+			var delta = (e.Delta.Y != 0 ? e.Delta.Y : e.Delta.X) * step;
+			var x = Math.Clamp(BreadcrumbScroll.Offset.X - delta, 0, max);
+			BreadcrumbScroll.Offset = BreadcrumbScroll.Offset.WithX(x);
+			e.Handled = true;
+		}
+
 		void OnClearSearchClick(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
 		{
 			viewModel.SearchText = string.Empty;
diff --git a/ILSpy/Controls/Omnibar/OmnibarScrollConverters.cs b/ILSpy/Controls/Omnibar/OmnibarScrollConverters.cs
new file mode 100644
index 000000000..caf89dede
--- /dev/null
+++ b/ILSpy/Controls/Omnibar/OmnibarScrollConverters.cs
@@ -0,0 +1,76 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Globalization;
+
+using Avalonia;
+using Avalonia.Data.Converters;
+
+namespace ICSharpCode.ILSpy.Controls.Omnibar
+{
+	/// <summary>
+	/// Adapters that let a plain horizontal <c>ScrollBar</c> drive and reflect a
+	/// <c>ScrollViewer</c>'s scroll state, which Avalonia exposes only as <c>Vector</c>/<c>Size</c>
+	/// (<c>Offset</c>, <c>ScrollBarMaximum</c>, <c>Viewport</c>) rather than the scalar
+	/// value/maximum/viewport a <c>ScrollBar</c> binds to. Used by the omnibar's overlay scrollbar
+	/// so the breadcrumb can scroll horizontally without the Simple theme's reserved scrollbar row.
+	/// </summary>
+	public static class OmnibarScrollConverters
+	{
+		/// <summary>
+		/// Two-way bridge between a <c>ScrollBar.Value</c> (double) and a <c>ScrollViewer.Offset</c>
+		/// (<see cref="Vector"/>): forward yields <c>Offset.X</c>; back rebuilds <c>(value, 0)</c>.
+		/// The omnibar disables vertical scrolling, so the Y component is always 0.
+		/// </summary>
+		public static readonly IValueConverter VectorX = new VectorXConverter();
+
+		/// <summary>Width of a <see cref="Size"/> (e.g. a <c>ScrollViewer.Viewport</c>).</summary>
+		public static readonly IValueConverter SizeWidth = new SizeWidthConverter();
+
+		/// <summary>True when a <see cref="Vector"/>'s X is greater than 0 (i.e. content overflows).</summary>
+		public static readonly IValueConverter VectorXPositive = new VectorXPositiveConverter();
+
+		sealed class VectorXConverter : IValueConverter
+		{
+			public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+				=> value is Vector v ? v.X : 0d;
+
+			public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+				=> new Vector(value is double d ? d : 0d, 0d);
+		}
+
+		sealed class SizeWidthConverter : IValueConverter
+		{
+			public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+				=> value is Size s ? s.Width : 0d;
+
+			public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+				=> throw new NotSupportedException();
+		}
+
+		sealed class VectorXPositiveConverter : IValueConverter
+		{
+			public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+				=> value is Vector v && v.X > 0;
+
+			public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+				=> throw new NotSupportedException();
+		}
+	}
+}