After playing for the Golden State Warriors' Summer League team in 2016, he signed with Spanish club Herbalife Gran Canaria for the 2016–17 season.

After playing for the Utah Jazz in the 2017 NBA Summer League, he was signed to the team for the 2017–18 season due to the exception left in the contract with Žalgiris Kaunas.

[5] O'Neale made his NBA debut on October 21, 2017, playing a single minute in their 96–87 win against the Oklahoma City Thunder.

[7] After the game on November 12, 2019, against the Brooklyn Nets, O’Neale traded jerseys with former Baylor Bears teammate Taurean Prince.

[9] On November 17, O'Neale put up 11 points, alongside a game-winning tip, with 10 rebounds, and 11 assists for his first career triple-double in a 109–107 win over the Portland Trail Blazers.