He made his international debut off the reserve bench in the first Test of the 1978 domestic series against New Zealand and then started in the 2nd Test. He was selected for the 1978 Kangaroo tour but played only four tour matches with his rival Tommy Raudonikis the selectors' preferred Test halfback. Oliphant and Raudonikis enjoyed a great club and state rivalry and regularly competed for national selection. Oliphant played in the inaugural State of Origin match for the Queensland Maroons. He later coached in the BRL premiership with Norths.