Thomas Simpson (1825–1908) was a British architect associated with the seaside town of Brighton. As architect to the Brighton and Preston School Board and the equivalent institution in neighbouring Hove, he designed "a distinguished group of board schools" during the late 19th century, when the provision of mass education was greatly extended. Many of these schools survive and some have listed status. He also worked on five Nonconformist chapels for various Christian denominations, using a wide variety of materials and architectural styles. He was the father of Sir John William Simpson and Gilbert Murray Simpson, who both became architects.

Sir John William Simpson KBE FRIBA was a British architect and President of the Royal Institute of British Architects from 1919 to 1921.