As a junior in 2009–10, he averaged 24.2 points, 9.8 rebounds and 3.2 blocks per game while leading Antonian to the TAPPS 5A state semifinals.

[1] Holmes played four seasons of college basketball for the University of Texas, averaging 9.2 points and 5.9 rebounds in 23.1 minutes over 127 career games.

[16] For the 2019–20 season, Holmes joined the Austin Spurs of the G League for training camp, but did not make the final roster.

He joined Kumanovo of the Macedonian league in 2021, averaging 11.9 points, 6.1 rebounds, 1.5 assists and 1.3 steals per game.

[17] Holmes was a member of the senior United States national team at the 2017 FIBA AmeriCup, where he won a gold medal.

Holmes' older sister, Amber, played basketball for four years at Southeast Missouri State (2009–12), while his younger brother, Sterling, attended Richland College in Dallas, then transferred to Texas Lutheran University in Seguin.