diff --git a/CHANGELOG.md b/CHANGELOG.md
index 60e88cfeb9..396414425a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,7 +17,7 @@ Changed:
 Fixed:
 - Fix inconsistency in margin application between `ComposeUiBox` and `ViewBox`.
 - Add support for the Height modifier in `ComposeUiBox`.
-
+- Add support for the Width modifier in `ComposeUiBox`.
 
 ## [0.16.0] - 2024-11-19
 [0.16.0]: https://github.com/cashapp/redwood/releases/tag/0.16.0
diff --git a/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/Box.kt b/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/Box.kt
index 7349ff5e64..df5d88661d 100644
--- a/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/Box.kt
+++ b/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/Box.kt
@@ -68,7 +68,8 @@ internal data class BoxChildLayoutInfo(
   val alignment: Alignment,
   val matchParentWidth: Boolean,
   val matchParentHeight: Boolean,
-  val requestedHeight: Dp?
+  val requestedHeight: Dp?,
+  val requestedWidth: Dp?
 )
 
 @PublishedApi
@@ -105,7 +106,13 @@ internal data class BoxMeasurePolicy(
           minWidth = if (boxWidth != Constraints.Infinity) boxWidth else 0,
           maxWidth = boxWidth,
         )
+      } else if (layoutInfo.requestedWidth != null) {
+        childConstraints = childConstraints.copy(
+          minWidth = layoutInfo.requestedWidth.toPx().toInt(),
+          maxWidth = layoutInfo.requestedWidth.toPx().toInt(),
+        )
       }
+
       if (layoutInfo.matchParentHeight) {
         childConstraints = childConstraints.copy(
           minHeight = if (boxHeight != Constraints.Infinity) boxHeight else 0,
diff --git a/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/ComposeUiBox.kt b/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/ComposeUiBox.kt
index 4c3aaecd18..191e8b6d95 100644
--- a/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/ComposeUiBox.kt
+++ b/redwood-layout-composeui/src/commonMain/kotlin/app/cash/redwood/layout/composeui/ComposeUiBox.kt
@@ -87,6 +87,7 @@ internal class ComposeUiBox(
     var matchParentWidth = matchParentWidth
     var matchParentHeight = matchParentHeight
     var requestedHeight: Dp? = null
+    var requestedWidth: Dp? = null
 
     forEachScoped { childModifier ->
       when (childModifier) {
@@ -107,7 +108,7 @@ internal class ComposeUiBox(
         }
 
         is Width -> {
-          // TODO
+          requestedWidth = childModifier.width.toDp()
         }
 
         is Height -> {
@@ -137,6 +138,7 @@ internal class ComposeUiBox(
       matchParentWidth = matchParentWidth,
       matchParentHeight = matchParentHeight,
       requestedHeight = requestedHeight,
+      requestedWidth = requestedWidth,
     )
   }
 
diff --git a/redwood-layout-composeui/src/test/snapshots/images/app.cash.redwood.layout.composeui_ComposeUiBoxTest_RTL_testChildExplicitWidth.png b/redwood-layout-composeui/src/test/snapshots/images/app.cash.redwood.layout.composeui_ComposeUiBoxTest_RTL_testChildExplicitWidth.png
new file mode 100644
index 0000000000..d54ce9a669
--- /dev/null
+++ b/redwood-layout-composeui/src/test/snapshots/images/app.cash.redwood.layout.composeui_ComposeUiBoxTest_RTL_testChildExplicitWidth.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3a553d58662b204b25c163bbfc76152373867326b855edd9053a1856798d4858
+size 10644
diff --git a/redwood-layout-composeui/src/test/snapshots/images/app.cash.redwood.layout.composeui_ComposeUiBoxTest_testChildExplicitWidth.png b/redwood-layout-composeui/src/test/snapshots/images/app.cash.redwood.layout.composeui_ComposeUiBoxTest_testChildExplicitWidth.png
new file mode 100644
index 0000000000..fcdd400300
--- /dev/null
+++ b/redwood-layout-composeui/src/test/snapshots/images/app.cash.redwood.layout.composeui_ComposeUiBoxTest_testChildExplicitWidth.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:960f69a6c71e22288756be21e3918ee055fbcbc212395fc6fe97118f5f993b61
+size 10611
diff --git a/redwood-layout-shared-test/src/commonMain/kotlin/app/cash/redwood/layout/AbstractBoxTest.kt b/redwood-layout-shared-test/src/commonMain/kotlin/app/cash/redwood/layout/AbstractBoxTest.kt
index a09fa185f1..78bdddf425 100644
--- a/redwood-layout-shared-test/src/commonMain/kotlin/app/cash/redwood/layout/AbstractBoxTest.kt
+++ b/redwood-layout-shared-test/src/commonMain/kotlin/app/cash/redwood/layout/AbstractBoxTest.kt
@@ -629,4 +629,36 @@ abstract class AbstractBoxTest<T : Any> {
 
     snapshotter.snapshot()
   }
+
+  @Test
+  fun testChildExplicitWidth() {
+    val container = box()
+      .apply {
+        width(Constraint.Fill)
+        height(Constraint.Fill)
+        horizontalAlignment(CrossAxisAlignment.Center)
+        verticalAlignment(CrossAxisAlignment.Stretch)
+      }
+    val snapshotter = snapshotter(container.value)
+
+    val box = box()
+      .apply {
+        modifier = MarginImpl(all = 24.dp)
+        width(Constraint.Wrap)
+        height(Constraint.Fill)
+        horizontalAlignment(CrossAxisAlignment.Center)
+        verticalAlignment(CrossAxisAlignment.Stretch)
+      }
+      .also { container.children.insert(0, it) }
+
+    widgetFactory.color().apply {
+      modifier = WidthImpl(200.dp)
+    }.also { box.children.insert(0, it) }
+
+    widgetFactory.text(
+      text = "foreground",
+    ).also { box.children.insert(1, it) }
+
+    snapshotter.snapshot()
+  }
 }
diff --git a/redwood-layout-uiview/RedwoodLayoutUIViewTests/__Snapshots__/UIViewBoxTestHost/testChildExplicitWidth.1.png b/redwood-layout-uiview/RedwoodLayoutUIViewTests/__Snapshots__/UIViewBoxTestHost/testChildExplicitWidth.1.png
new file mode 100644
index 0000000000..0ad81ddbc8
--- /dev/null
+++ b/redwood-layout-uiview/RedwoodLayoutUIViewTests/__Snapshots__/UIViewBoxTestHost/testChildExplicitWidth.1.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fa8dc3351d50a0fb35dfbfa4c75a0512c20cb915533e496e5751ce1829fddfeb
+size 104589
diff --git a/redwood-layout-view/src/test/snapshots/images/app.cash.redwood.layout.view_ViewBoxTest_RTL_testChildExplicitWidth.png b/redwood-layout-view/src/test/snapshots/images/app.cash.redwood.layout.view_ViewBoxTest_RTL_testChildExplicitWidth.png
new file mode 100644
index 0000000000..328f4276dd
--- /dev/null
+++ b/redwood-layout-view/src/test/snapshots/images/app.cash.redwood.layout.view_ViewBoxTest_RTL_testChildExplicitWidth.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:29d13ff676ac18ca451c0cd3eb18ba48e9209adba3243e3417640ab61c778363
+size 13939
diff --git a/redwood-layout-view/src/test/snapshots/images/app.cash.redwood.layout.view_ViewBoxTest_testChildExplicitWidth.png b/redwood-layout-view/src/test/snapshots/images/app.cash.redwood.layout.view_ViewBoxTest_testChildExplicitWidth.png
new file mode 100644
index 0000000000..e3b23d555a
--- /dev/null
+++ b/redwood-layout-view/src/test/snapshots/images/app.cash.redwood.layout.view_ViewBoxTest_testChildExplicitWidth.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:ee1fd52be5ccb86228b5c488a79f2973d7d12df8951a3b778ffac0484a6d42e1
+size 13906