The 6-2 guard started 69 games in his two seasons at Kentucky and averaged 12.1 points, 5.4 rebounds and 4.2 assists this past season.
"[Big Blue Nation], thank you to the greatest fans in the entire world," Briscoe said in a statement. "It was a dream to play in front of BBN and an honor to wear K-E-N-T-U-C-K-Y across my chest. I'm ready for the next step and can't wait to begin the next journey."
Thank you Kentucky for an amazing 2 years..With that being said I've decided to enter the 2017 NBA Draft and will be signing with an agent. pic.twitter.com/8gDAsbofIH— Slim Bz (@ZayBriscoe) April 6, 2017
Briscoe, who averaged 10.9 points, 5.4 rebounds and 3.7 during his two seasons with the Wildcats, is the fourth player from this year's team to declare for the draft, joining freshmen De'Aaron Fox, Malik Monk and Bam Adebayo.
"Thank you to my brothers," Briscoe said. "We've been through so much together and accomplished even more. Thank you to my family and friends. Without your support, I wouldn't be where I am now."
Monk and Fox are both considered likely lottery picks, while several NBA executives told ESPN that Adebayo, who will maintain his eligibility by not yet signing with an agent, is a likely first-rounder. Briscoe is likely to be taken in the second round of the draft on June 22.
"Isaiah is a winner," Kentucky coach John Calipari said in a statement. "Physically and mentally he's a pit bull with skills with the ball. We averaged nearly 30 wins a season over the last two years and Isaiah played a big part in all of them. Isaiah defends, he rebounds and he creates shots for others. I am so proud of his improvement over his time here and am looking forward to seeing his continued growth at the next level."
Briscoe, who returned to UK after declaring for the draft last year, started 69 of 70 games during his career, and he became just the third player in school history to get a triple-double -- getting 19 points, 10 rebounds and 11 assists against Ole Miss on Dec. 29.