Williams, a 6-foot-4 guard from Midlothian, Virginia, was originally committed to VCU, but reopened his recruitment after coach Shaka Smart left for Texas. The late addition of the four-star recruit fills a big need with his outside shooting.
Maye, the son of former UNC quarterback Mark Maye, is a 6-foot-7 instate forward and two-time Associated Press all-state pick.
Coach Roy Williams says Luke Maye committed last fall but was ''extremely loyal'' and waited to sign in case UNC needed to use the scholarship elsewhere.
UNC returns nine of its top 10 scorers from last year's run to the NCAA Sweet 16.