He was a Labor Party member of the New South Wales Legislative Assembly from 1962 to 1965, representing the electorate of Nepean.
Bennett was born in Cargo, and educated at various Roman Catholic schools in New South Wales.
Bennett was selected to contest the local seat of Nepean for Labor at the 1962 state election.
An electoral redistribution had changed the long-time Liberal seat into a notional Labor seat, and Bennett won a tight race against the incumbent Liberal member, Bill Chapman.
He was only to serve one term, however; he was narrowly defeated at the 1965 election by Liberal candidate Ron Dunbier.