He is the second child of National Basketball Association (NBA) player LeBron James and the younger brother of college basketball player Bronny James. James primarily plays the shooting guard position. As of March 2024 he is 6 feet 6 inches (1.98 m) tall and weighs 180 pounds (82 kg).

James played in a scrimmage on Tuesday after participating in drills the previous day, when he had his vertical leap measured at 40 1/2 inches and his height — without shoes — at 6-foot-1 1/2 despite being listed by Southern California as 6-4.

Bryce James turned 14 years old on June 14, 2021. At that time, he was listed at 5 feet 11 inches tall on ESPN's recruiting profile.

In 2001, during the summer before his junior year, James was the subject of a feature article in Slam magazine in which writer Ryan Jones lauded the 16-year-old James, who had grown to 6 feet 7 inches (2.01 m), as "[possibly] the best high school basketball player in America right now".