diff --git a/mobile/app/h/[hostId]/index.tsx b/mobile/app/h/[hostId]/index.tsx
index 2673b57e527..3b62b787216 100644
--- a/mobile/app/h/[hostId]/index.tsx
+++ b/mobile/app/h/[hostId]/index.tsx
@@ -44,6 +44,7 @@ import {
 import type { RpcSuccess } from '../../../src/transport/types'
 import { StatusDot } from '../../../src/components/StatusDot'
 import { NewWorktreeModalController } from '../../../src/components/NewWorktreeModalController'
+import { NewWorkspaceFab, FAB_SIZE } from '../../../src/components/NewWorkspaceFab'
 import { MobileRepoIcon } from '../../../src/components/MobileRepoIcon'
 import { WorktreeListRow } from '../../../src/components/WorktreeListRow'
 import { useNow } from '../../../src/hooks/use-now'
@@ -1099,17 +1100,6 @@ export function HostScreen({
               />
             </Pressable>
 
-            <Pressable
-              style={styles.newButton}
-              onPress={openNewWorktreeModal}
-              disabled={connState !== 'connected'}
-            >
-              <Plus
-                size={16}
-                color={connState === 'connected' ? colors.textPrimary : colors.textMuted}
-              />
-            </Pressable>
-
             <Pressable style={styles.searchToggle} onPress={() => setShowSearch((s) => !s)}>
               {showSearch ? (
                 <X size={16} color={colors.textSecondary} />
@@ -1187,7 +1177,9 @@ export function HostScreen({
           // above the Samsung 3-button nav / iOS home indicator.
           contentContainerStyle={[
             styles.list,
-            { paddingBottom: spacing.lg + insets.bottom },
+            // Phone shows a floating "+" button bottom-right; reserve room so the
+            // last row stays tappable above it. Embedded sidebars keep the toolbar +.
+            { paddingBottom: (embedded ? spacing.lg : FAB_SIZE + spacing.xl) + insets.bottom },
             isWideLayout &&
               !embedded && { maxWidth: contentMaxWidth, width: '100%', alignSelf: 'center' }
           ]}
@@ -1245,6 +1237,11 @@ export function HostScreen({
         />
       )}
 
+      {/* Floating "new workspace" button — phone only; embedded sidebars keep the toolbar +. */}
+      {!embedded && (
+        <NewWorkspaceFab onPress={openNewWorktreeModal} disabled={connState !== 'connected'} />
+      )}
+
       <PickerModal
         visible={showSortPicker}
         title="Sort By"
@@ -1610,9 +1607,6 @@ const styles = StyleSheet.create({
   toolbarIconDisabled: {
     opacity: 0.6
   },
-  newButton: {
-    padding: spacing.xs
-  },
   searchToggle: {
     padding: spacing.xs
   },
diff --git a/mobile/src/components/NewWorkspaceFab.tsx b/mobile/src/components/NewWorkspaceFab.tsx
new file mode 100644
index 00000000000..0c10b315999
--- /dev/null
+++ b/mobile/src/components/NewWorkspaceFab.tsx
@@ -0,0 +1,63 @@
+import { Pressable, StyleSheet } from 'react-native'
+import { useSafeAreaInsets } from 'react-native-safe-area-context'
+import { Plus } from 'lucide-react-native'
+import { colors, spacing } from '../theme/mobile-theme'
+
+// Diameter of the phone "new workspace" floating action button. Exported so the
+// worktree list can reserve matching bottom padding and keep the last row tappable.
+export const FAB_SIZE = 48
+
+type NewWorkspaceFabProps = {
+  onPress: () => void
+  disabled?: boolean
+}
+
+// Phone-only floating "+" for creating a workspace. Absolutely positioned so it
+// never intercepts list row taps, and lifted above the home indicator.
+export function NewWorkspaceFab({ onPress, disabled }: NewWorkspaceFabProps): React.JSX.Element {
+  const insets = useSafeAreaInsets()
+  return (
+    <Pressable
+      style={({ pressed }) => [
+        styles.fab,
+        { bottom: spacing.xl + insets.bottom },
+        pressed && styles.fabPressed,
+        disabled && styles.fabDisabled
+      ]}
+      onPress={onPress}
+      disabled={disabled}
+      accessibilityRole="button"
+      accessibilityLabel="New workspace"
+      hitSlop={8}
+    >
+      <Plus size={24} color={colors.bgBase} strokeWidth={2.75} />
+    </Pressable>
+  )
+}
+
+const styles = StyleSheet.create({
+  fab: {
+    position: 'absolute',
+    right: spacing.lg,
+    width: FAB_SIZE,
+    height: FAB_SIZE,
+    borderRadius: FAB_SIZE / 2,
+    alignItems: 'center',
+    justifyContent: 'center',
+    // Crisp near-white surface + dark icon: high contrast against the dark canvas
+    // reads as the primary action while staying monochrome (STYLEGUIDE: color is
+    // for state). Tight shadow avoids the muddy halo that made it look disabled.
+    backgroundColor: colors.surfaceBright,
+    shadowColor: '#000',
+    shadowOpacity: 0.25,
+    shadowRadius: 4,
+    shadowOffset: { width: 0, height: 2 },
+    elevation: 4
+  },
+  fabPressed: {
+    backgroundColor: colors.textPrimary
+  },
+  fabDisabled: {
+    opacity: 0.5
+  }
+})
diff --git a/mobile/src/theme/mobile-theme.ts b/mobile/src/theme/mobile-theme.ts
index 5583b73f078..76b14415a32 100644
--- a/mobile/src/theme/mobile-theme.ts
+++ b/mobile/src/theme/mobile-theme.ts
@@ -12,6 +12,11 @@ export const colors = {
   textSecondary: '#888888',
   textMuted: '#555555',
 
+  // Crisp near-white surface for the single primary action on a screen (the
+  // worktree FAB). Brighter than textPrimary so it reads as a solid button, not
+  // disabled chrome, while staying monochrome (STYLEGUIDE: color is for state).
+  surfaceBright: '#f5f5f5',
+
   accentBlue: '#3b82f6',
 
   statusGreen: '#22c55e',