[1][4] His mother, Grace Ndidi Okereke,[3] was a track and field athlete who competed at a national level for Nigeria and died of cancer when Anunoby was one year old.

[5] At the age of four, Anunoby moved with his family to the U.S. and settled in Jefferson City, Missouri,[2] where his father was a professor of finance at Lincoln University.

[5] His older brother, Chigbo, played in the NFL for the Cleveland Browns, Tennessee Titans, and Minnesota Vikings before entering medical school.

[8] In October 2014, Anunoby chose to attend Indiana University[9] over Georgia, Iowa, George Mason, and Ole Miss.

[13] On 10 April 2017, Anunoby declared his intention to enter the 2017 NBA draft and hire an agent, ending his tenure with the Hoosiers.

By 15 December, he led starter rookies in offensive and defensive rating and had the third highest true shooting percentage and best turnover-to-assist ratio for a non-guard.

[18] On 29 January 2019, Anunoby was named a member of the World Team representing the United Kingdom for the 2019 Rising Stars Challenge.

[22] He hit a game-winning buzzer-beater three-pointer on 3 September, in a 104–103 win in Game 3 of the Eastern Conference semifinals against the Boston Celtics, and finished with 12 points.

[32] On 30 December 2023, Anunoby, along with Precious Achiuwa and Malachi Flynn were traded to the New York Knicks in exchange for RJ Barrett, Immanuel Quickley and a second-round pick.