diff --git a/guides/components.md b/guides/components.md
index 46afd4c4..0df96aec 100644
--- a/guides/components.md
+++ b/guides/components.md
@@ -199,6 +199,10 @@ cancel_tap = {self(), :cancel}
 """
 ```
 
+A single weighted child expands into the parent's remaining main-axis space. Multiple
+weighted children divide that space evenly on iOS; Android additionally honors unequal
+numeric ratios. Weight values must be positive. Use equal weights for cross-platform layouts.
+
 ### `:box`
 
 A single-child container. Use it to add background, padding, or corner radius to a child:
diff --git a/ios/MobNode.h b/ios/MobNode.h
index ec830e07..5082c9f8 100644
--- a/ios/MobNode.h
+++ b/ios/MobNode.h
@@ -173,7 +173,8 @@ NS_ASSUME_NONNULL_BEGIN
 @property(nonatomic, strong, nullable) UIColor *color; // track / indicator color
 
 // Layout behaviour
-@property(nonatomic) BOOL fillWidth; // fill parent width (default NO; button default YES)
+@property(nonatomic) CGFloat layoutWeight; // positive = expand on a row/column's main axis
+@property(nonatomic) BOOL fillWidth;       // fill parent width (default NO; button default YES)
 @property(nonatomic)
     BOOL fillHeight; // fill parent height (default NO) — used for full-screen overlays/dialogs
 @property(nonatomic) CGFloat cornerRadius; // rounded corners in pt (default 0)
diff --git a/ios/MobNode.m b/ios/MobNode.m
index e9f442c7..9bc81320 100644
--- a/ios/MobNode.m
+++ b/ios/MobNode.m
@@ -35,6 +35,7 @@ - (instancetype)init {
         _contentModeStr = @"fit";
         _fixedWidth = 0.0;
         _fixedHeight = 0.0;
+        _layoutWeight = 0.0;
         _fillWidth = NO;
         _cornerRadius = 0.0;
         _nativeViewHandle = -1;     // -1 = no native component slot assigned (MOB-100)
diff --git a/ios/MobRootView.swift b/ios/MobRootView.swift
index 26a20068..32397c48 100644
--- a/ios/MobRootView.swift
+++ b/ios/MobRootView.swift
@@ -47,6 +47,11 @@ public final class MobNativeViewRegistry {
     }
 }
 
+enum MobLayoutWeightAxis {
+    case horizontal
+    case vertical
+}
+
 extension View {
     @ViewBuilder
     func ifLet<T>(_ value: T?, transform: (Self, T) -> some View) -> some View {
@@ -241,13 +246,21 @@ extension MobNode {
 
 struct MobNodeView: View {
     let node: MobNode
+    private let layoutWeightAxis: MobLayoutWeightAxis?
+
+    init(node: MobNode, layoutWeightAxis: MobLayoutWeightAxis? = nil) {
+        self.node = node
+        self.layoutWeightAxis = layoutWeightAxis
+    }
 
     var body: some View {
         Group {
             switch node.nodeType {
             case .column:
                 VStack(alignment: .leading, spacing: 0) {
-                    ForEach(Array(node.childNodes.enumerated()), id: \.offset) { _, child in MobNodeView(node: child) }
+                    ForEach(Array(node.childNodes.enumerated()), id: \.offset) { _, child in
+                        MobNodeView(node: child, layoutWeightAxis: .vertical)
+                    }
                 }
                 // fill_height: true lets a column flex to fill its parent so children
                 // with Spacer() or fill_height of their own can pin to the bottom.
@@ -272,7 +285,9 @@ struct MobNodeView: View {
                     }
                 }()
                 HStack(alignment: alignment, spacing: 0) {
-                    ForEach(Array(node.childNodes.enumerated()), id: \.offset) { _, child in MobNodeView(node: child) }
+                    ForEach(Array(node.childNodes.enumerated()), id: \.offset) { _, child in
+                        MobNodeView(node: child, layoutWeightAxis: .horizontal)
+                    }
                 }
                 // Without maxWidth: .infinity an HStack hugs its content.
                 // Flex Spacers inside then have nothing to expand into and
@@ -513,6 +528,12 @@ struct MobNodeView: View {
                 EmptyView()
             }
         }
+        // Weight sizing must wrap the node's own visual decoration. Applying
+        // the frame from the parent after MobNodeView has painted its
+        // background leaves an expanded transparent region around a
+        // content-sized fill. Repaint that decoration on the weighted frame
+        // so iOS matches Compose's weight-before-nodeModifier ordering.
+        .modifier(MobLayoutWeight(node: node, axis: layoutWeightAxis))
         // Per-node offset — applied uniformly to every node type. Default is
         // (0, 0) which is a no-op. Used by SquareTriangle's hexagonal
         // snowflake to position rings absolutely within a center-aligned box.
@@ -524,6 +545,36 @@ struct MobNodeView: View {
     }
 }
 
+private struct MobLayoutWeight: ViewModifier {
+    let node: MobNode
+    let axis: MobLayoutWeightAxis?
+
+    @ViewBuilder
+    func body(content: Content) -> some View {
+        if node.layoutWeight > 0, let axis {
+            switch axis {
+            case .horizontal:
+                decorate(content.frame(maxWidth: .infinity, alignment: .leading))
+            case .vertical:
+                decorate(content.frame(maxHeight: .infinity, alignment: .top))
+            }
+        } else {
+            content
+        }
+    }
+
+    private func decorate(_ content: some View) -> some View {
+        content
+            .mobBoxBackground(node: node)
+            .overlay(
+                RoundedRectangle(cornerRadius: node.cornerRadius)
+                    .stroke(node.borderColor.map { Color($0) } ?? Color.clear,
+                            lineWidth: node.borderWidth)
+                    .allowsHitTesting(false)
+            )
+    }
+}
+
 // MobFrameTracker — for any node with an :id, set it as the accessibility
 // identifier and report the element's global frame (logical points) to the C
 // registry as it lays out / moves. Untagged nodes pass through untouched, so
diff --git a/ios/mob_nif.m b/ios/mob_nif.m
index 9253e4d9..6a857d2b 100644
--- a/ios/mob_nif.m
+++ b/ios/mob_nif.m
@@ -1073,6 +1073,10 @@ static void mob_send_change_float(int handle, double value) {
         if (fixedHeight)
             node.fixedHeight = [fixedHeight doubleValue];
 
+        id layoutWeight = props[@"weight"];
+        if (layoutWeight)
+            node.layoutWeight = [layoutWeight doubleValue];
+
         id cornerRadius = props[@"corner_radius"];
         if (cornerRadius)
             node.cornerRadius = [cornerRadius doubleValue];
diff --git a/test/mob/native_layout_weight_test.exs b/test/mob/native_layout_weight_test.exs
new file mode 100644
index 00000000..3b9297a1
--- /dev/null
+++ b/test/mob/native_layout_weight_test.exs
@@ -0,0 +1,29 @@
+# These source-contract tests guard native SwiftUI behavior that Elixir cannot execute.
+# credo:disable-for-this-file Jump.CredoChecks.VacuousTest
+defmodule Mob.NativeLayoutWeightTest do
+  use ExUnit.Case, async: true
+
+  @ios Path.expand("../../ios", __DIR__)
+
+  test "iOS parses layout weight at the native boundary" do
+    header = File.read!(Path.join(@ios, "MobNode.h"))
+    implementation = File.read!(Path.join(@ios, "MobNode.m"))
+    nif = File.read!(Path.join(@ios, "mob_nif.m"))
+
+    assert header =~ "CGFloat layoutWeight"
+    assert implementation =~ "_layoutWeight = 0.0"
+    assert nif =~ ~s|props[@"weight"]|
+    assert nif =~ "node.layoutWeight = [layoutWeight doubleValue]"
+  end
+
+  test "iOS expands weighted children on their parent's main axis" do
+    source = File.read!(Path.join(@ios, "MobRootView.swift"))
+
+    assert source =~ "MobNodeView(node: child, layoutWeightAxis: .vertical)"
+    assert source =~ "MobNodeView(node: child, layoutWeightAxis: .horizontal)"
+    assert source =~ ".modifier(MobLayoutWeight(node: node, axis: layoutWeightAxis))"
+    assert source =~ "frame(maxHeight: .infinity, alignment: .top)"
+    assert source =~ "frame(maxWidth: .infinity, alignment: .leading)"
+    assert source =~ ".mobBoxBackground(node: node)"
+  end
+end