Starting in his freshman season, O'Neal played basketball for
Windward School in Los Angeles at the
forward position. His highlight videos immediately helped him gain popularity on the Internet and appeared in
The Washington Post. However, he received limited playing time because the team's six seniors earned the most minutes. Head coach Steve Smith viewed O'Neal's first season with Windward as a "learning year" and expected him to assume a larger role in the following season. In May 2015, O'Neal received a scholarship offer from
USC, his first from an
NCAA Division I program. In the following months, he had additional offers from
Baylor,
LSU,
UCLA, and
Kansas State. O'Neal remained with Windward as a sophomore and saw significant improvement. In October 2015, at a tournament in
Fairfax High School that featured many top high school teams in the nation, O'Neal scored 23 points in a loss to
Bishop Alemany. O'Neal, in December, drew attention from scouts at the
MaxPreps Holiday Classic despite his team's struggles. He became known as a versatile
swingman with ball-handling, shooting, and defending skills. On June 29, 2016, the
Los Angeles Times announced that O'Neal would transfer to
Crossroads School in Santa Monica. He joined the team expected to take a leading role with top high school recruit Ira Lee. On January 6, 2017, O'Neal scored 15 points in a 54–50 win over
Brentwood.
Recruiting in 2017 In April 2017, O'Neal committed to play college basketball for
Arizona. On February 24, 2018, he decommitted from Arizona immediately following
allegations by ESPN that FBI wiretaps had intercepted phone conversations between Arizona coach
Sean Miller and an agent discussing paying $100,000 to ensure star player
Deandre Ayton signed with Arizona. Because he signed a nonbinding financial aid agreement with Arizona instead of a formal
letter of intent, he did not require a release from Arizona to seek out a new school. O'Neal verbally committed to
UCLA on February 27, but he did not sign a
National Letter of Intent during the signing period that ended on May 16. He signed with the Bruins in August. ==College career==