 After leaving football, Trezise pursued a political career with the Labor Party.He stood unsuccessfully for the Victorian Legislative Assembly seat of Geelong in 1961, but won the seat of Geelong West in 1964, and held the seat and its subsequent successor Geelong North until 1992.In 1982 he became Minister for Youth, Sport and Recreation (from 1985 just Minister for Sport and Recreation), a portfolio he held until 1992—throughout the entire terms of Premiers John Cain and Joan Kirner.