Noel's eligibility came into question this past summer when NCAA officials reportedly began investigating his recruitment process.
But Kentucky coach John Calipari confirmed Wednesday that the NCAA has cleared Noel's eligibility during an interview on "SportsCenter."
"He's been cleared to practice and cleared to play games," Calipari said during the interview. "Everything's good to go."
SI.com reported in August that two NCAA enforcement officials visited Noel's New Hampshire prep school to ask about the star forward's recruitment process.
The NCAA investigated people involved in Noel's recruitment and Noel's payment for unofficial visits, according to SI.com, which cited "a person with knowledge of the NCAA inquiry." In May, the two NCAA officials also traveled to Noel's high school in Massachusetts.
But NCAA vice president of communications Bob Williams confirmed to ESPN.com's Dana O'Neil that Noel is cleared to practice and compete.
Noel is the top-ranked incoming freshman on the 2012 ESPN 100 and is the favorite to be the No. 1 pick in the 2013 NBA draft, according to ESPN Insider Chad Ford.
"(The challenge) is figuring out how we play," Calipari said Wednesday. "Most coaches will come back and have an idea -- this is what we're going to run, here's how we're going to do it. ... How do you get into that stuff with the team we have? What if I have to play Willie Cauley and Nerlens together -- that's 7-foot and 6-foot-10."
The Wildcats opened the season ranked third in the USA Today coaches' preseason poll, released Wednesday, despite losing the top six players from last season's national championship squad.
Calipari said Wednesday that he expects the Wildcats to struggle early this season as the young players, including Noel, learn how to adapt to the college game.
"It's even hard to practice because when we put (the freshmen) in practice together, they're real good because there's no one to play against," he said during the "SportsCenter" interview. "I like my team, but we're just not going to be that good early. By the end of the year, I think we'll be all right."