Oklahoma State promoted assistant Mike Boynton to head coach less than a week after Brad Underwood left for Illinois.
Oklahoma State announced the decision on its website Friday.
Boynton, 35, helped engineer Oklahoma State's run to the NCAA Tournament last season. He was an assistant for Underwood for three years at Stephen F. Austin and helped the Lumberjacks win 89 games.
Before heading to Stephen F. Austin, Boynton spent four years as an assistant at South Carolina. He played for South Carolina and earned a degree in African-American studies.
Boynton knows he has a rare opportunity for a young man, yet he feels his age doesn't matter.
At age 35, he feels ready and believes it was a matter of time before he'd get a chance to run a program.
"I don't think about my age when it comes to this thing," he said Monday at his introductory news conference.
Underwood left Oklahoma State after one year. The Cowboys lost their first six Big 12 games before rallying down the stretch to finish 9-9 in league play. The Cowboys were among the nation's highest-scoring teams.