Leonard Joseph Quilty (March 27, 1920 – May 14, 2014) was a Canadian politician, who represented Renfrew South in the Legislative Assembly of Ontario from 1962 to 1963 as a Liberal member. He was elected in a by-election after the death of PC MPP James Anthony Maloney in October 1961. He was defeated in the general election held in 1963. While an MPP, Quilty served on six Standing Committees. He died in Bonnechere Manor in 2014 and was buried in Holywell Cemetery, both in Renfrew, Ontario.