diff --git a/apps/web/src/actions/reminders.ts b/apps/web/src/actions/reminders.ts
new file mode 100644
index 0000000..cd48e30
--- /dev/null
+++ b/apps/web/src/actions/reminders.ts
@@ -0,0 +1,42 @@
+"use server";
+
+import { revalidatePath } from "next/cache";
+import { redirect } from "next/navigation";
+import { headers } from "next/headers";
+import { eq } from "drizzle-orm";
+import { reminders } from "@cmbot/db";
+import { db } from "@/lib/db";
+import { getSeededOperator } from "@/lib/operator";
+import { checkRateLimit } from "@/lib/rate-limit";
+
+async function rateLimit(key: string) {
+  const h = await headers();
+  const ip = h.get("x-forwarded-for")?.split(",")[0]?.trim() ?? h.get("x-real-ip") ?? "unknown";
+  const r = await checkRateLimit(`${key}:${ip}`, { max: 30, windowSec: 10 });
+  if (r.limited) throw new Error("Too many requests");
+}
+
+export async function deleteReminderAction(formData: FormData): Promise<void> {
+  await rateLimit("delete-reminder");
+  const reminderId = formData.get("reminderId");
+  if (typeof reminderId !== "string") return;
+
+  const op = await getSeededOperator();
+  const reminder = await db.query.reminders.findFirst({
+    where: (r, { eq }) => eq(r.id, reminderId),
+  });
+  if (!reminder) return;
+
+  // Verify ownership via the account
+  const account = await db.query.whatsappAccounts.findFirst({
+    where: (a, { eq, and }) => and(eq(a.id, reminder.accountId), eq(a.operatorId, op.id)),
+  });
+  if (!account) return;
+
+  // Cascading FKs (reminder_runs + reminder_targets + reminder_messages) clean up.
+  // pg-boss job for this reminder will fire and find the row gone (soft cancel).
+  await db.delete(reminders).where(eq(reminders.id, reminderId));
+
+  revalidatePath("/reminders" as any);
+  redirect("/reminders" as any);
+}
diff --git a/apps/web/src/app/reminders/[id]/delete-dialog.tsx b/apps/web/src/app/reminders/[id]/delete-dialog.tsx
index 9c3d8c1..8f6c0b0 100644
--- a/apps/web/src/app/reminders/[id]/delete-dialog.tsx
+++ b/apps/web/src/app/reminders/[id]/delete-dialog.tsx
@@ -12,24 +12,14 @@ import {
   DialogTitle,
   DialogTrigger,
 } from "@/components/ui/dialog";
+import { deleteReminderAction } from "@/actions/reminders";
 
 interface DeleteDialogProps {
-  deleteAction: () => Promise<void>;
+  reminderId: string;
 }
 
-export function DeleteDialog({ deleteAction }: DeleteDialogProps) {
+export function DeleteDialog({ reminderId }: DeleteDialogProps) {
   const [open, setOpen] = useState(false);
-  const [pending, setPending] = useState(false);
-
-  async function handleConfirm() {
-    setPending(true);
-    try {
-      await deleteAction();
-    } finally {
-      setPending(false);
-      setOpen(false);
-    }
-  }
 
   return (
     <Dialog open={open} onOpenChange={setOpen}>
@@ -48,14 +38,16 @@ export function DeleteDialog({ deleteAction }: DeleteDialogProps) {
           </DialogDescription>
         </DialogHeader>
         <DialogFooter>
-          <Button
-            variant="destructive"
-            size="sm"
-            disabled={pending}
-            onClick={handleConfirm}
-          >
-            {pending ? "Deleting…" : "Delete"}
-          </Button>
+          <form action={deleteReminderAction} className="flex gap-2">
+            <input type="hidden" name="reminderId" value={reminderId} />
+            <Button
+              variant="destructive"
+              size="sm"
+              type="submit"
+            >
+              Delete
+            </Button>
+          </form>
         </DialogFooter>
       </DialogContent>
     </Dialog>
diff --git a/apps/web/src/app/reminders/[id]/page.tsx b/apps/web/src/app/reminders/[id]/page.tsx
index e27cb49..8500e9e 100644
--- a/apps/web/src/app/reminders/[id]/page.tsx
+++ b/apps/web/src/app/reminders/[id]/page.tsx
@@ -73,13 +73,6 @@ function StatusPill({ status }: { status: string }) {
   );
 }
 
-// ---------------------------------------------------------------------------
-// Server action (no-op placeholder — real delete wired in Task 19)
-// ---------------------------------------------------------------------------
-async function _deleteReminderStub() {
-  "use server";
-  // wired in Task 19
-}
 
 // ---------------------------------------------------------------------------
 // Page
@@ -242,7 +235,7 @@ export default async function ReminderDetailPage({ params }: Props) {
 
       {/* Action footer */}
       <div className="flex items-center justify-end pt-2 border-t">
-        <DeleteDialog deleteAction={_deleteReminderStub} />
+        <DeleteDialog reminderId={reminder.id} />
       </div>
     </div>
   );