Okafor joins Corey Maggette (1999), Luol Deng (2004), Kyrie Irving (2011), Austin Rivers (2012) and Jabari Parker (2014) as Blue Devils who entered the draft after their freshman seasons. Each was selected among the first 13 players in their drafts, with Irving going No. 1 in 2011.
Two of Okafor's classmates -- Justise Winslow and Tyus Jones, the most outstanding player at the Final Four -- also are serious candidates to jump to the pros.
"What a great decision," Krzyzewski said in the release. "This is a tremendous opportunity for Jahlil, and he has earned it."
Okafor led Duke (35-4) to its fifth national championship, a 68-63 victory over Wisconsin in Indianapolis on Monday night. Okafor had told reporters Wednesday that "it would kind of suck" to only get to play a few months alongside longtime friend Jones, adding that whatever he decided would have to be a "business decision."
Okafor was Duke's 16th first-team All-American and the Blue Devils' second freshman All-American in as many years, with Parker chosen last season.Okafor would be just the seventh Duke player 6-foot-10 or taller under Krzyzewski to be drafted in the first round and the first Duke player 6-10 or taller to leave school early and be drafted in the first round.
"Obviously, he has done an incredible job here at Duke and he will always be a part of our Duke basketball family," Krzyzewski said. "We could not be happier for he and his family."
Okafor, who averaged 17.3 points and 8.5 rebounds while shooting 66 percent, was the first freshman in Atlantic Coast Conference history to be named league player of the year.
"As early as I can remember, I've fantasized and dreamed of the day that I could play professional basketball," Okafor said in the statement. " I recall at the age of 6, promising my mom and dad that when I made it to the NBA I would buy them both different colored trucks. They would laugh with me in support and encouraged me to dream big and work hard.
"With that being said and now at the age of 19, my dream is still alive."
Information from The Associated Press and ESPN's Stats & Information was used in this report.
Jahlil Okafor declares for NBA draft
Jeff Goodman breaks down Jahlil Okafor's decision to declare for the NBA draft and whether he'll be the top overall pick.