The 6-foot-9, 215-pound Knox, considered a potential lottery pick, made the announcement Friday afternoon. Knox led Kentucky in scoring at 15.6 points per game and grabbed 5.4 boards per contest.
"After careful consideration, I have made the decision to follow my dreams of becoming an NBA player and enter the 2018 NBA draft," Knox said in a statement. "Thank you to my teammates, my coaches and the fans. You have made my year as a Kentucky Wildcat one of the best years of my life. God bless."
Knox joins fellow freshman PJ Washington as Kentucky players to have declared for the draft. Washington, however, has not signed with an agent, meaning he could return to school.
Point guard Shai Gilgeous-Alexander, also considered a potential lottery pick by NBA executives, has yet to make an official announcement. Sources told ESPN that Gilgeous-Alexander is leaning toward joining Knox and leaving after one season in Lexington.
Redshirt freshman Hamidou Diallo, who considered leaving last season, has yet to decide whether he will declare. Sophomore Wenyen Gabriel and freshmen Nick Richards and Jarred Vanderbilt could also test the draft process.
"Kevin came in as one of the youngest freshmen in the country and adapted as well as any player I have ever coached," Kentucky coach John Calipari said in a statement. "He improved in every area of his game, became an efficient scorer like some of the best players I've coached here and could score all types of ways, including runners, pull-ups, 3-pointers, post-ups and in pick-and-roll offense. His defense and rebounding improved throughout the year, which is a big reason why we were able to go on a run at the end of the season."