The 6-foot-11 All-American announced his decision Thursday, saying he will fulfill one of his earliest childhood dreams.
"As early as I can remember, I've fantasized and dreamed of the day that I could play professional basketball," Okafor said in a statement issued by the school.
Coach Mike Krzyzewski called it a "great decision."
"This is a tremendous opportunity for Jahlil and he has earned it," Krzyzewski said. "Obviously, he has done an incredible job here at Duke and he will always be a part of our Duke basketball family. We could not be happier for [him] and his family."
The announcement came three days after Okafor led Duke (35-4) to its fifth national championship, a 68-63 victory against Wisconsin in Indianapolis on Monday night.
It also caught no one off guard.
Okafor arrived at Duke last summer as one of the nation's top recruits.
He was both a preseason and postseason AP All-America selection, averaged 17.3 points and 8.5 rebounds and shot 66 percent -- all team bests -- and became the first freshman in Atlantic Coast Conference history to be named league player of the year. He also led the team with a 15-point average during the NCAA Tournament.
And while he told reporters Wednesday that "it would kind of suck" to only get to play a few months alongside longtime friend Tyus Jones, he said whatever he decided would have to be a "business decision."
"My freshman year has been an amazing experience, to say the least," Okafor said. "It exceeded my expectations. I love Cameron and Duke University. I can't thank my coaches, teammates and family enough for making this year so special and helping me grow on and off the court."
Okafor becomes Duke's sixth one-and-done player and its fourth in five years, with the most recent additions to that club being Kyrie Irving, Austin Rivers and Jabari Parker.
There could be more: Two of Okafor's classmates -- Justise Winslow and Jones, the most outstanding player at the Final Four -- also are serious candidates to jump to the pros.
This article was from The Associated Press and was legally licensed through the NewsCred publisher network.