diff --git a/src/renderer/src/components/sidebar/DeleteWorktreeDialog.tsx b/src/renderer/src/components/sidebar/DeleteWorktreeDialog.tsx
index 1e84f7532d9..872c1dae81a 100644
--- a/src/renderer/src/components/sidebar/DeleteWorktreeDialog.tsx
+++ b/src/renderer/src/components/sidebar/DeleteWorktreeDialog.tsx
@@ -34,6 +34,10 @@ const DeleteWorktreeDialog = React.memo(function DeleteWorktreeDialog() {
   const deleteError = deleteState?.error ?? null
   const canForceDelete = deleteState?.canForceDelete ?? false
   const worktreeName = worktree?.displayName ?? 'unknown'
+  // Why: the main worktree is the repo's original clone directory — `git worktree remove`
+  // always rejects it. We block the delete button upfront so the user doesn't have to
+  // discover this limitation via a confusing force-delete dead-end.
+  const isMainWorktree = worktree?.isMainWorktree ?? false
 
   useEffect(() => {
     if (isOpen && worktreeId && !worktree && !isDeleting) {
@@ -127,7 +131,19 @@ const DeleteWorktreeDialog = React.memo(function DeleteWorktreeDialog() {
           </div>
         )}
 
-        {deleteError && (
+        {isMainWorktree && (
+          <div className="rounded-md border border-blue-500/40 bg-blue-500/8 px-3 py-2 text-xs text-blue-700 dark:text-blue-300">
+            <div className="flex items-start gap-2">
+              <AlertTriangle className="mt-0.5 size-3.5 shrink-0" />
+              <div className="min-w-0 flex-1">
+                This is the <span className="font-semibold">main worktree</span> (the original clone
+                directory). Git does not allow removing the main worktree.
+              </div>
+            </div>
+          </div>
+        )}
+
+        {deleteError && !isMainWorktree && (
           <div className="rounded-md border border-destructive/40 bg-destructive/8 px-3 py-2 text-xs text-destructive">
             <div className="flex items-start gap-2">
               <AlertTriangle className="mt-0.5 size-3.5 shrink-0" />
@@ -138,19 +154,28 @@ const DeleteWorktreeDialog = React.memo(function DeleteWorktreeDialog() {
 
         <DialogFooter>
           <Button variant="outline" onClick={() => handleOpenChange(false)} disabled={isDeleting}>
-            Cancel
+            {isMainWorktree ? 'Close' : 'Cancel'}
           </Button>
-          {canForceDelete ? (
-            <Button variant="destructive" onClick={() => handleDelete(true)} disabled={isDeleting}>
-              {isDeleting ? <LoaderCircle className="size-4 animate-spin" /> : <Trash2 />}
-              {isDeleting ? 'Force Deleting…' : 'Force Delete'}
-            </Button>
-          ) : (
-            <Button variant="destructive" onClick={() => handleDelete(false)} disabled={isDeleting}>
-              {isDeleting ? <LoaderCircle className="size-4 animate-spin" /> : <Trash2 />}
-              {isDeleting ? 'Deleting…' : 'Delete'}
-            </Button>
-          )}
+          {!isMainWorktree &&
+            (canForceDelete ? (
+              <Button
+                variant="destructive"
+                onClick={() => handleDelete(true)}
+                disabled={isDeleting}
+              >
+                {isDeleting ? <LoaderCircle className="size-4 animate-spin" /> : <Trash2 />}
+                {isDeleting ? 'Force Deleting…' : 'Force Delete'}
+              </Button>
+            ) : (
+              <Button
+                variant="destructive"
+                onClick={() => handleDelete(false)}
+                disabled={isDeleting}
+              >
+                {isDeleting ? <LoaderCircle className="size-4 animate-spin" /> : <Trash2 />}
+                {isDeleting ? 'Deleting…' : 'Delete'}
+              </Button>
+            ))}
         </DialogFooter>
       </DialogContent>
     </Dialog>
diff --git a/src/renderer/src/components/sidebar/WorktreeCard.tsx b/src/renderer/src/components/sidebar/WorktreeCard.tsx
index ce389d5a4d7..278bc3cb2f3 100644
--- a/src/renderer/src/components/sidebar/WorktreeCard.tsx
+++ b/src/renderer/src/components/sidebar/WorktreeCard.tsx
@@ -351,6 +351,9 @@ const WorktreeCard = React.memo(function WorktreeCard({
               </div>
             )}
 
+            {/* Branch / folder badge — unchanged from the original logic so we
+               never lose the branch name, even when the main worktree is checked
+               out on a non-primary branch like "feature-x". */}
             {isFolder ? (
               <Badge
                 variant="secondary"
@@ -359,18 +362,55 @@ const WorktreeCard = React.memo(function WorktreeCard({
                 {repo ? getRepoKindLabel(repo) : 'Folder'}
               </Badge>
             ) : isPrimaryBranch(worktree.branch) ? (
-              <Badge
-                variant="secondary"
-                className="h-[16px] px-1.5 text-[10px] font-medium rounded shrink-0 text-muted-foreground bg-accent border border-border dark:bg-accent/80 dark:border-border/50 leading-none"
-              >
-                main
-              </Badge>
+              worktree.isMainWorktree ? (
+                <Tooltip>
+                  <TooltipTrigger asChild>
+                    <Badge
+                      variant="outline"
+                      className="h-[16px] px-1.5 text-[10px] font-medium rounded shrink-0 leading-none text-blue-600 border-blue-500/30 bg-blue-500/5 dark:text-blue-400 dark:border-blue-400/30 dark:bg-blue-400/5"
+                    >
+                      main
+                    </Badge>
+                  </TooltipTrigger>
+                  <TooltipContent side="right" sideOffset={8}>
+                    Main worktree
+                  </TooltipContent>
+                </Tooltip>
+              ) : (
+                <Badge
+                  variant="secondary"
+                  className="h-[16px] px-1.5 text-[10px] font-medium rounded shrink-0 leading-none text-muted-foreground bg-accent border border-border dark:bg-accent/80 dark:border-border/50"
+                >
+                  main
+                </Badge>
+              )
             ) : (
               <span className="text-[11px] text-muted-foreground truncate leading-none">
                 {branch}
               </span>
             )}
 
+            {/* Why: the main worktree (the original clone directory) cannot be
+               deleted via `git worktree remove`. Surfacing this in the card lets
+               users identify it at a glance. When the branch is already primary,
+               the blue "main" badge above does double duty; otherwise we add a
+               separate blue badge so both the branch and worktree type are visible. */}
+            {worktree.isMainWorktree && !isFolder && !isPrimaryBranch(worktree.branch) && (
+              <Tooltip>
+                <TooltipTrigger asChild>
+                  <Badge
+                    variant="outline"
+                    className="h-[16px] px-1.5 text-[10px] font-medium rounded shrink-0 text-blue-600 border-blue-500/30 bg-blue-500/5 dark:text-blue-400 dark:border-blue-400/30 dark:bg-blue-400/5 leading-none"
+                  >
+                    main
+                  </Badge>
+                </TooltipTrigger>
+                <TooltipContent side="right" sideOffset={8}>
+                  Main worktree
+                </TooltipContent>
+              </Tooltip>
+            )}
+
             {/* Why: the conflict operation (merge/rebase/cherry-pick) is the
                only signal that the worktree is in an incomplete operation state.
                Showing it on the card lets the user spot worktrees that need
diff --git a/src/renderer/src/components/sidebar/WorktreeContextMenu.tsx b/src/renderer/src/components/sidebar/WorktreeContextMenu.tsx
index 2a9ddee0382..c1b8869890b 100644
--- a/src/renderer/src/components/sidebar/WorktreeContextMenu.tsx
+++ b/src/renderer/src/components/sidebar/WorktreeContextMenu.tsx
@@ -176,7 +176,20 @@ const WorktreeContextMenu = React.memo(function WorktreeContextMenu({ worktree,
             <XCircle className="size-3.5" />
             Shutdown
           </DropdownMenuItem>
-          <DropdownMenuItem variant="destructive" onSelect={handleDelete} disabled={isDeleting}>
+          {/* Why: `git worktree remove` always rejects the main worktree, so we
+             disable the item upfront. Radix forwards unknown props to the DOM
+             element, so `title` works directly without a wrapper span — this
+             preserves Radix's flat roving-tabindex keyboard navigation. */}
+          <DropdownMenuItem
+            variant="destructive"
+            onSelect={handleDelete}
+            disabled={isDeleting || (!isFolder && worktree.isMainWorktree)}
+            title={
+              !isFolder && worktree.isMainWorktree
+                ? 'The main worktree cannot be deleted'
+                : undefined
+            }
+          >
             <Trash2 className="size-3.5" />
             {isDeleting ? 'Deleting…' : isFolder ? 'Remove Folder from Orca' : 'Delete'}
           </DropdownMenuItem>