 In February 2015, Cartwright joined the North Queensland Cowboys as an assistant to head coach Paul Green.On 4 October 2015, Cartwright was a member of the Cowboys' coaching staff in the side's 17-16 Grand Final victory over the Brisbane Broncos.In the weeks following the Grand Final win, Cartwright quit the Cowboys and returned to Sydney as an assistant coach of the Manly-Warringah Sea Eagles.