Looney is ranked as the 20th prospect in the draft class by DraftExpress.com. Players have the option of receiving feedback on their likely draft position from an advisory committee, but Looney didn't utilize it.
"This was a really tough decision for me because there were so many positives both ways," Looney said in a statement. "My time at UCLA has been unbelievable, and I know I'll be a Bruin forever. But playing in the NBA is a dream I've had for so long, and this feels like the right time to pursue that dream and make the transition to the next level."
As a freshman, Looney led the team with 9.2 rebounds and contributed 11.6 points per game. His 15 double-doubles led all freshmen nationally.
Looney's departure leaves a void, particularly on the boards, but the Bruins are deepest in the frontcourt. Forward Tony Parker will return as a senior starter. Thomas Welsh, at 7 feet, played more minutes than any other bench player. Gyorgy Goloman and Wanaah Bail, who missed the second half of the season after being declared academically ineligible, also will return.
The most likely candidate to take over Looney's role is Jonah Bolden, who had to sit out his first season at UCLA after being declared academically ineligible. Bolden has practiced with the team since January.
Looney will become the fourth UCLA player in two seasons under UCLA Coach Steve Alford to declare for the draft as an underclassman. Earlier in the season, Looney said he spoke with two of last season's early departures, Memphis Grizzlies guard Jordan Adams and San Antonio Spurs guard Kyle Anderson. Looney is a fan of the Lakers, who could have a lottery pick this summer.
Alford said he supported Looney's decision.
"It's difficult because on one hand, I couldn't be more excited for Kevon," Alford said in a statement, "while on the other, the realization hits you that we're losing one of the finest young men that I've ever had an opportunity to coach."