Stanley Herbert Hartt, OC QC (born 1937) is a Canadian lawyer, lecturer, businessman, and civil servant. He was Chief of Staff to Canadian Prime Minister Brian Mulroney from 1989 to 1990.Born in Montreal, Quebec, the son of Maurice Hartt, a Quebec MNA and MP, and brother of the late Joel Hartt (1940-2009), he received a Bachelor of Arts degree in 1958, a Master of Arts degree in 1961, and a Bachelor of Civil Law degree in 1963 from McGill University.