Architect. Born in Edinburgh, the son of a joiner, Cousin was a pupil of William Henry Playfair (1789 - 1857). He specialised in the design of churches, garden cemeteries and mausoleums. His work included Dalry, Dean, Newington and Warriston Cemeteries in Edinburgh, and the Menteith Mausoleum in the Glasgow Necropolis. He also laid out East Princes Street Gardens in Edinburgh.
Cousin is buried at Dean Cemetery.