The Former Geological Survey of Canada Building (French: Ancien édifice de la Commission géologique du Canada) is a three-storey, stone building located at the intersection of Sussex Drive and George Street in the Byward Market area of Ottawa, Ontario, Canada. It is named for its former occupant, the Geological Survey of Canada. The building was designated a National Historic Site of Canada in 1955 as it is one of the oldest remaining buildings in Ottawa, and over the years it has served as home to various public and cultural institutions.