The 6-foot-1, 165-pounder averaged 26.4 points, 3.3 assists, 3.0 rebounds and 2.5 steals per game last season for Cardinal Mooney High School in Sarasota, Florida. McMahon also shot 51 percent from 3-point range and 83 percent from the foul line and led the school to its first state final four appearance.
McMahon was named to the Florida Class 3A all-tournament team and finished third in the state's Mr. Basketball voting.
Cardinals coach Rick Pitino said in a release that McMahon will likely redshirt next season and build his strength but added that he will be "an integral part of our team in future years."