Kent initially worked as a primary school teacher, teaching for three years in Nambour and Buderim in Queensland while acting in amateur theatre groups. Kent moved to Sydney to train as an actor with the Independent Drama School in the early 1960s, supporting himself during this time with teaching.
In Sydney he understudied the role of Rolfe in the Tivoli Theatre's production of The Sound of Music, and acted in Beckett and Oh Dad Poor Dad Momma's Locked You in the Closet and I'm Feelin' So Sad with the Independent. After two years in Sydney he emigrated to the UK. He spent ten years there, during which time he worked with the Royal Shakespeare Company. On returning to Sydney in 1974, Kent played Frank'N'Furter in a stage production of The Rocky Horror Show.
Several appearances on Australian television followed, including roles in Rush, The Sullivans, Cop Shop and Carson's Law. He moved to Melbourne in 1984 and in 1984–1985 appeared in television soap opera Prisoner as the villainous Frank Burke for several months.
Kent, who was homosexual, learned he was HIV positive in the mid 1980s and at that time volunteered as a care-taker for people living with HIV and AIDS. He was public about his HIV status and directed two theatre productions for Out Theatre Company that addressed HIV and AIDS. One of these, Unnatural Acts, toured pubs, theatres and colleges in Melbourne and Sydney.