King's architect and surveyor in Scotland. Reid was responsible for many public works, primarily in Edinburgh, including the Law Courts in Parliament Square. He also worked on the detailed layout of Robert Adam's Charlotte Square after that architect's death and built a house there for himself. In the square he completed the design for St. George's Church (now West Register House), which had again been started by Adam. Reid planned the northern part of Edinburgh's New Town (1802) and extended Adam's Register House (1834). He also worked in Perth, on Paxton House in the Scottish Borders and provided advice on Elgin Cathedral.
He is buried in Dean Cemetery in Edinburgh.