He began his career in the Australian NBL in 2020, playing his first season for the Cairns Taipans.

[6] In 2019, King joined the NBA Global Academy, a training centre at the Australian Institute of Sport in Canberra.

In association with the academy, he played for the BA Centre of Excellence in the NBL1, an Australian semi-professional league.

[5] Later that year, King represented Queensland South at the Australian Under-18 Championships, where he led the competition in scoring with 26.6 points per game.

[7][8] By joining the NBL, he turned down offers from several NCAA Division I programs, including Arizona, Baylor, Oregon and Virginia.

[15] He became just the third New Zealand-born player to be picked in the NBA draft, following Sean Marks and Steven Adams.

[17] In October 2023, he joined the Indiana Mad Ants, the Pacers' NBA G League affiliate.