Sir William Mulock (January 19,1844 - October 1,1944) was a Canadian politician and cabinet member. Born in Scotland, Mulock became rector at the University of Toronto in 1924 and served in that capacity until his death at age 100 in 1944. He won a seat in the Canadian House of Commons and served there from 1882 - 1905, while also holding the postion of Postmaster General from 1896 - 1905. In 1900, Mulock himself established the Department of Labor, becoming its first secretary that same year and served until 1905. In 1923, Mulock was appointed as Chief Justice of the Supreme Court of Ontario, a position he held until 1936. From 1931 to 1932 he served as acting Lieutenant Governor of Ontario.