The indie band, fronted by Ricky Wilson, will play within the walls of the castle on July 21, 2023.
Tickets to the general public only went on sale a week ago after a 48-hour priority release to local postcodes.
Gemma England, general manager at Ludlow Castle said: "We are once again, blown away by the demand.
Following the sell-out Bastille summer 2023 date, Kaiser Chiefs now joins the bill as the second sell-out announcement of the Within the Walls series.
"Regional tickets sales have surpassed expectations and we couldn’t be more excited to be working with Future Sound Group to bring these exciting events to Ludlow."