Coombefield Quarry is an active stone quarry located on the Isle of Portland, Dorset, England. It is situated near the island's southernmost village Southwell. The large quarry has been worked over many years, and has two voids known as Coombefield North and Coombefield South. The quarry today incorporates the former Suckthumb Quarry, which is situated at the northwest part of the quarry, and is now filled in. The quarry is owned by Portland Stone Firms Ltd, along with Broadcroft and Perryfield Quarry. The firm is the largest landholder on the island.