Thorp Arch Trading Estate is a trading estate, with both industrial and retail space, 3 miles (5 km) south-east of Wetherby in the City of Leeds metropolitan borough, West Yorkshire, England. The estate occupies the major part of the site of a former Royal Ordnance Factory (ROF), ROF Thorp Arch, in the parishes of Thorp Arch and Walton. There is evidence of its former use around the site which was similar in layout to the former ROF Aycliffe in Darlington, County Durham.