The school announced Wednesday all three players have declared for the NBA draft but will not sign with an agent, clearing the way for them to return to school this fall if they change their minds by May 8.
Jones and Knight are considered mid-to-high first-round picks; Liggins is a defensive stopper who hopes to play his way into the first round after being evaluated by scouts.
The trio helped the Wildcats to their first Final Four appearance in 13 years this spring. Kentucky fell to Connecticut in the national semifinals.
The 6-foot-3 Knight averaged 17.3 points at point guard and proved to be one of the best clutch performers in the country, hitting a pair of game-winning shots during the team's NCAA tournament run.
His driving layup helped Kentucky escape an upset bid by Princeton in the second round and his pull-up jumper with 5 seconds left allowed the Wildcats to knock off top-seeded Ohio State in the regional semifinals.
"Playing in the NBA has always been a dream of mine and this is the next step," Knight said. "All season long Coach has been tutoring me on the fine points of being a point guard, and now I have an opportunity to put my game on display in front of NBA scouts as a result of my hard work."
Knight's 657 points were the most by a Kentucky freshman; he also broke the school's freshman 3-point record by knocking down 87 of them.
Jones averaged 15.7 points, 8.8 rebounds and 1.9 blocks and set a Kentucky freshman record with a 35-point performance in a victory over Auburn in January. He was chosen SEC Newcomer of the Year by The Associated Press.
The 6-8 power forward volunteered to take on a slightly lesser role during the postseason to allow his teammates to get more involved, a move coach John Calipari said was key to the team's postseason success.
Liggins will have the most to prove. He blossomed into one of the country's top defenders, but remains limited offensively. He averaged 8.6 points and 4.0 rebounds while leading the team with 46 steals.
"Growing up in a tough environment in Chicago, it's a pleasure to have an opportunity to do something special," said Liggins, who welcomed his first child during the season. "This is another challenge I'm looking forward to, to have my game evaluated by pro scouts and see how I rank against some of the top players in the world."
Calipari encouraged all three players to test their prospects but added he would "would love the opportunity to continue to coach them again next season."
The coach told reporters last week the unstable NBA labor situation could throw a wrench into his players' plans to leave early.
The collective bargaining agreement between the NBA Players Association and the owners expires June 30. If a new deal can't be reached, there's a chance league owners could lock out the players.
"The lockout really kind of screws everything up because a lot of kids are pulling their names because what if the lockout goes the whole year?" Calipari said. "What kind of mistake did you make?"
The announcement comes one day after freshman guard Doron Lamb said he would return this fall. Lamb pointed to the Final Four loss and another talented incoming freshman class as the main reasons behind his decision.
Lamb's return guarantees at least one high-profile freshman will return, one more than a year ago when Kentucky lost freshmen John Wall, DeMarcus Cousins, Eric Bledsoe and Daniel Orton to the pros after just one season on campus.
Hall of Fame coach and ESPN analyst Bobby Knight criticized Kentucky for promoting the "one-and-done" culture during the weekend, but backed off his statements Tuesday.
Knight said in a brief statement released by ESPN: "My overall point is that 'one-and-dones' are not healthy for college basketball. I should not have made it personal to Kentucky and its players and I apologize."