Willis was released on a $50 bond paid by his mother, Linda Potts. No further details were provided concerning his arrest.
A Kentucky spokesperson said the program is aware of the situation, but has yet to offer an official comment.
The 6-foot-9 Willis averaged 7.7 points and 4.0 rebounds per game last season for the Wildcats.He played in 32 games, starting 11.
A native of Mount Washington, Ky., Willis would be UK's leading 3-point shooter (44 percent) and free-throw shooter (89 percent) entering the 2016-17 season.