The Honourable Louis Orville Breithaupt (1890-1960), served as the 18th Lieutenant Governor of Ontario from 1952 to 1957.

Louis Breithaupt was born in 1890 in Berlin (later Kitchener), Ontario, and was educated at the University of Toronto. He rose to become head of his family's leather business in Kitchener. He was a Member of Parliament from 1940 to 1952. Breithaupt was appointed Lieutenant Governor of Ontario in 1952 and served until 1957. He was active in many service groups, such as the YMCA and Rotary Club. He became Chancellor of Victoria University in 1959, and died in Toronto in 1960.