diff --git a/app/admin/guests/[id]/actions.ts b/app/admin/guests/[id]/actions.ts
new file mode 100644
index 0000000..2114217
--- /dev/null
+++ b/app/admin/guests/[id]/actions.ts
@@ -0,0 +1,64 @@
+"use server"
+
+import { revalidatePath } from "next/cache"
+import { redirect } from "next/navigation"
+
+import { auth } from "@/auth"
+import { isAdminEmail } from "@/lib/admin-auth"
+import { deleteInvitationGroup } from "@/lib/db/queries/invitations"
+import { deleteUploadObject } from "@/lib/storage/uploads"
+import { deleteInvitationSchema } from "@/lib/validation/invitation"
+
+export interface DeleteInvitationActionState {
+  error: string | null
+}
+
+export async function deleteInvitationAction(
+  _previousState: DeleteInvitationActionState,
+  formData: FormData,
+): Promise<DeleteInvitationActionState> {
+  const session = await auth()
+  const adminEmail = session?.user?.email
+
+  if (!isAdminEmail(adminEmail)) {
+    return { error: "You are not allowed to delete invitations." }
+  }
+
+  const authorizedAdminEmail = adminEmail ?? ""
+
+  const parsed = deleteInvitationSchema.safeParse({
+    invitationId: formData.get("invitationId"),
+  })
+
+  if (!parsed.success) {
+    return { error: "Could not delete this guest group." }
+  }
+
+  let deleted: Awaited<ReturnType<typeof deleteInvitationGroup>>
+
+  try {
+    deleted = await deleteInvitationGroup(parsed.data.invitationId, authorizedAdminEmail)
+  } catch (error) {
+    console.error("Failed to delete invitation group", error)
+    return { error: "Could not delete this guest group. Please try again." }
+  }
+
+  if (!deleted) {
+    return { error: "This guest group was already removed." }
+  }
+
+  if (deleted.photoObjectKey) {
+    try {
+      await deleteUploadObject(deleted.photoObjectKey)
+    } catch (error) {
+      console.error("Failed to delete uploaded photo object", {
+        invitationId: deleted.id,
+        objectKey: deleted.photoObjectKey,
+        error,
+      })
+    }
+  }
+
+  revalidatePath("/admin/guests")
+  redirect("/admin/guests?deleted=1")
+}
diff --git a/app/admin/guests/[id]/page.tsx b/app/admin/guests/[id]/page.tsx
index e43d6d0..44025a0 100644
--- a/app/admin/guests/[id]/page.tsx
+++ b/app/admin/guests/[id]/page.tsx
@@ -2,6 +2,7 @@ import Link from "next/link"
 import { notFound } from "next/navigation"
 
 import { CopyInviteButton } from "@/components/admin/copy-invite-button"
+import { DeleteInvitationDialog } from "@/components/admin/delete-invitation-dialog"
 import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert"
 import { Badge } from "@/components/ui/badge"
 import { Button } from "@/components/ui/button"
@@ -104,11 +105,15 @@ export default async function GuestDetailPage({
           </h1>
           <p className="text-muted-foreground">Invitation details and member list.</p>
         </div>
-        <div className="flex gap-2">
+        <div className="flex flex-wrap gap-2">
           <Button asChild variant="outline">
             <Link href="/admin/guests">Back to list</Link>
           </Button>
           <CopyInviteButton inviteUrl={inviteUrl} />
+          <DeleteInvitationDialog
+            invitationId={detail.invitation.id}
+            displayName={detail.invitation.display_name}
+          />
         </div>
       </div>
 
diff --git a/app/admin/guests/page.tsx b/app/admin/guests/page.tsx
index 6d4cc41..232bd92 100644
--- a/app/admin/guests/page.tsx
+++ b/app/admin/guests/page.tsx
@@ -1,6 +1,7 @@
 import Link from "next/link"
 
 import { CopyInviteButton } from "@/components/admin/copy-invite-button"
+import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert"
 import { Badge } from "@/components/ui/badge"
 import { Button } from "@/components/ui/button"
 import {
@@ -33,7 +34,12 @@ function getStatusVariant(status: string): "default" | "secondary" | "outline" {
   return "outline"
 }
 
-export default async function GuestsPage() {
+export default async function GuestsPage({
+  searchParams,
+}: {
+  searchParams: Promise<{ deleted?: string }>
+}) {
+  const { deleted } = await searchParams
   const invitations = await listInvitations()
 
   return (
@@ -50,6 +56,15 @@ export default async function GuestsPage() {
         </Button>
       </div>
 
+      {deleted ? (
+        <Alert>
+          <AlertTitle>Guest group deleted</AlertTitle>
+          <AlertDescription>
+            The invitation and its associated guest information were permanently removed.
+          </AlertDescription>
+        </Alert>
+      ) : null}
+
       <Card>
         <CardHeader>
           <CardTitle>Invitation list</CardTitle>
diff --git a/components/admin/delete-invitation-dialog.tsx b/components/admin/delete-invitation-dialog.tsx
new file mode 100644
index 0000000..6030abe
--- /dev/null
+++ b/components/admin/delete-invitation-dialog.tsx
@@ -0,0 +1,75 @@
+"use client"
+
+import { useActionState, useState } from "react"
+import { useFormStatus } from "react-dom"
+
+import {
+  AlertDialog,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from "@/components/ui/alert-dialog"
+import { Button } from "@/components/ui/button"
+import type { DeleteInvitationActionState } from "@/app/admin/guests/[id]/actions"
+import { deleteInvitationAction } from "@/app/admin/guests/[id]/actions"
+
+interface DeleteInvitationDialogProps {
+  invitationId: string
+  displayName: string
+}
+
+const initialState: DeleteInvitationActionState = { error: null }
+
+function DeleteSubmitButton() {
+  const { pending } = useFormStatus()
+
+  return (
+    <Button type="submit" variant="destructive" disabled={pending}>
+      {pending ? "Deleting..." : "Delete permanently"}
+    </Button>
+  )
+}
+
+export function DeleteInvitationDialog({
+  invitationId,
+  displayName,
+}: DeleteInvitationDialogProps) {
+  const [open, setOpen] = useState(false)
+  const [state, formAction] = useActionState(deleteInvitationAction, initialState)
+
+  return (
+    <AlertDialog open={open} onOpenChange={setOpen}>
+      <AlertDialogTrigger asChild>
+        <Button variant="destructive">Delete group</Button>
+      </AlertDialogTrigger>
+      <AlertDialogContent>
+        <form action={formAction} className="space-y-4">
+          <input type="hidden" name="invitationId" value={invitationId} />
+
+          <AlertDialogHeader>
+            <AlertDialogTitle>Delete {displayName}?</AlertDialogTitle>
+            <AlertDialogDescription>
+              This permanently removes this invitation group, its members, RSVP information,
+              toast requests, and uploaded photo. This action cannot be undone.
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+
+          {state.error ? (
+            <p className="rounded-md border border-destructive/30 bg-destructive/10 px-3 py-2 text-sm text-destructive">
+              {state.error}
+            </p>
+          ) : null}
+
+          <AlertDialogFooter>
+            <AlertDialogCancel type="button">Cancel</AlertDialogCancel>
+            <DeleteSubmitButton />
+          </AlertDialogFooter>
+        </form>
+      </AlertDialogContent>
+    </AlertDialog>
+  )
+}
diff --git a/components/ui/alert-dialog.tsx b/components/ui/alert-dialog.tsx
new file mode 100644
index 0000000..ff37090
--- /dev/null
+++ b/components/ui/alert-dialog.tsx
@@ -0,0 +1,148 @@
+"use client"
+
+import * as React from "react"
+import { AlertDialog as AlertDialogPrimitive } from "radix-ui"
+
+import { buttonVariants } from "@/components/ui/button"
+import { cn } from "@/lib/utils"
+
+function AlertDialog({
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Root>) {
+  return <AlertDialogPrimitive.Root data-slot="alert-dialog" {...props} />
+}
+
+function AlertDialogTrigger({
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Trigger>) {
+  return (
+    <AlertDialogPrimitive.Trigger data-slot="alert-dialog-trigger" {...props} />
+  )
+}
+
+function AlertDialogPortal({
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Portal>) {
+  return (
+    <AlertDialogPrimitive.Portal data-slot="alert-dialog-portal" {...props} />
+  )
+}
+
+function AlertDialogOverlay({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Overlay>) {
+  return (
+    <AlertDialogPrimitive.Overlay
+      data-slot="alert-dialog-overlay"
+      className={cn(
+        "fixed inset-0 z-50 bg-black/50 data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:animate-in data-[state=open]:fade-in-0",
+        className,
+      )}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogContent({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Content>) {
+  return (
+    <AlertDialogPortal>
+      <AlertDialogOverlay />
+      <AlertDialogPrimitive.Content
+        data-slot="alert-dialog-content"
+        className={cn(
+          "fixed top-[50%] left-[50%] z-50 grid w-full max-w-[calc(100%-2rem)] translate-x-[-50%] translate-y-[-50%] gap-4 rounded-lg border bg-background p-6 shadow-lg duration-200 data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=closed]:zoom-out-95 data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=open]:zoom-in-95 sm:max-w-lg",
+          className,
+        )}
+        {...props}
+      />
+    </AlertDialogPortal>
+  )
+}
+
+function AlertDialogHeader({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="alert-dialog-header"
+      className={cn("flex flex-col gap-2 text-center sm:text-left", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogFooter({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="alert-dialog-footer"
+      className={cn("flex flex-col-reverse gap-2 sm:flex-row sm:justify-end", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogTitle({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Title>) {
+  return (
+    <AlertDialogPrimitive.Title
+      data-slot="alert-dialog-title"
+      className={cn("text-lg font-semibold", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogDescription({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Description>) {
+  return (
+    <AlertDialogPrimitive.Description
+      data-slot="alert-dialog-description"
+      className={cn("text-sm text-muted-foreground", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogAction({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Action>) {
+  return (
+    <AlertDialogPrimitive.Action
+      className={cn(buttonVariants(), className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogCancel({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Cancel>) {
+  return (
+    <AlertDialogPrimitive.Cancel
+      className={cn(buttonVariants({ variant: "outline" }), className)}
+      {...props}
+    />
+  )
+}
+
+export {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogOverlay,
+  AlertDialogPortal,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+}
diff --git a/lib/db/queries/invitations.ts b/lib/db/queries/invitations.ts
index dfeb519..03d3b68 100644
--- a/lib/db/queries/invitations.ts
+++ b/lib/db/queries/invitations.ts
@@ -75,6 +75,69 @@ export async function createInvitationWithMembers(input: CreateInvitationInput)
   })
 }
 
+export interface DeletedInvitationResult {
+  id: string
+  displayName: string
+  photoObjectKey: string | null
+}
+
+export async function deleteInvitationGroup(
+  invitationId: string,
+  adminEmail: string,
+): Promise<DeletedInvitationResult | null> {
+  return db.transaction().execute(async (trx) => {
+    const invitation = await trx
+      .selectFrom("invitations")
+      .select(["id", "display_name", "token"])
+      .where("id", "=", invitationId)
+      .executeTakeFirst()
+
+    if (!invitation) return null
+
+    const photoUpload = await trx
+      .selectFrom("photo_uploads")
+      .select(["object_key"])
+      .where("invitation_id", "=", invitationId)
+      .executeTakeFirst()
+
+    const membersCount = await trx
+      .selectFrom("invitation_members")
+      .select((eb) => eb.fn.countAll<string>().as("count"))
+      .where("invitation_id", "=", invitationId)
+      .executeTakeFirst()
+
+    await trx
+      .insertInto("admin_audit_events")
+      .values({
+        admin_email: adminEmail,
+        action: "invitation.deleted",
+        target_type: "invitation",
+        target_id: invitationId,
+        metadata: {
+          displayName: invitation.display_name,
+          token: invitation.token,
+          membersCount: Number(membersCount?.count ?? 0),
+          photoObjectKey: photoUpload?.object_key ?? null,
+        },
+      })
+      .execute()
+
+    const deleted = await trx
+      .deleteFrom("invitations")
+      .where("id", "=", invitationId)
+      .returning(["id", "display_name"])
+      .executeTakeFirst()
+
+    if (!deleted) return null
+
+    return {
+      id: deleted.id,
+      displayName: deleted.display_name,
+      photoObjectKey: photoUpload?.object_key ?? null,
+    }
+  })
+}
+
 export async function listInvitations(): Promise<InvitationListItem[]> {
   const invitations = await db
     .selectFrom("invitations")
diff --git a/lib/validation/invitation.ts b/lib/validation/invitation.ts
index 357f737..e01e239 100644
--- a/lib/validation/invitation.ts
+++ b/lib/validation/invitation.ts
@@ -45,4 +45,9 @@ export const createInvitationSchema = z
     path: ["members"],
   })
 
+export const deleteInvitationSchema = z.object({
+  invitationId: z.uuid(),
+})
+
 export type CreateInvitationInput = z.infer<typeof createInvitationSchema>
+export type DeleteInvitationInput = z.infer<typeof deleteInvitationSchema>