Campbell contested his debut season in the Porsche Mobil 1 Supercup in 2017. This was his first year in European motorsport. Prior to that, the young man born in Warwick (Queensland) had raced in single-seaters, as well as in the national Porsche one-make cups in his homeland of Australia. In the Porsche Mobil 1 Supercup, Campbell finished runner-up in the rookie competition. After eleven races, he ended the season in third overall. Since 2018, he has tackled the FIA WEC for Dempsey Proton Racing. Campbell shares the cockpit of the No. 77 911 RSR with Porsche Junior Julien Andlauer and team owner Christian Ried. In 2018, the trio won the GTE-Am class of the Le Mans 24-hour race. Campbell kicked off the 2019 racing season with a brilliant victory at Bathurst (Australia).