After moving from Australia at a young age, Callum progressed through the youth ranks on a scholarship at Leicester and was rewarded with a professional contract in 2013.
Callum featured regularly in Leicester’s under 23s side, making over 40 appearances.
He gained valuable first team experience, impressing on loan at Mansfield, Peterborough, Brentford and Barnsley. He spent the 2017/18 season on loan at Wigan, who he helped to the League One title, making 27 appearances in League One and a further 6 in all competitions.
Callum joined Ipswich Town on loan in January 2019, making five appearances for the side.
After spending eight years at Leicester, Callum joined Hull City on a permanent move in Summer 2019.