Costume Shop Finder London Costume Shop Listings page. This section lists as many Costume Shops we could find in London. If you are the owner of a Costume Shop in London please submit your listing using the Get Listed link at the top. These London Costume Shops offer costumes and fancy dress for adults or children in London, including theatrical and party costumes, Halloween costumes and costume accessories. Most Costume Shops listed below also offer costume accessories such as masks, wigs, make up and props in London.