Frederick McIntosh Cass Q.C., C.D. ( August 5, 1913 – November 25, 2000) was a Canadian politician who served as both Attorney-General of Ontario and Speaker of the Legislative Assembly. He served as a Progressive Conservative Member of Provincial Parliament from 1955 until his retirement in 1971. Cass served in the Canadian Army during the Second World War from 1941 to 1945.