In the 1940s, Mitchelstown Co-operative Agricultural Society built a milk processing factory on the site of the castle, which it had purchased together with some of the demesne lands that surrounded it. The site is now owned by Dairygold Co-op. The coats of arms of Mitchelstown Castle are now held by a local writer and will be erected in Mitchelstown's new public library, which will also have a special section devoted to local history and especially Mitchelstown Castle and its owners.