The contract will be worth a guaranteed $4 million per year and keeps the 49-year-old at UCLA until the end of the 2026-27 season.
"In less than two years in Westwood - through seasons disrupted by a global pandemic - Mick has led UCLA men's basketball back to its rightful place among the nation's elite," said athletic director Martin Jarmond.
The No. 11 seeded Bruins were a major storyline at March Madness after becoming just the second team ever to go from the First Four to the Final Four.
Cronin joined the program prior to the 2019-20 season after 13 campaigns at Cincinnati, where he led the Bearcats to nine straight NCAA Tournaments.
"I love being at UCLA," said Cronin. "I would like to thank our players and my coaching staff for their continued commitment to build this basketball program into something of which we can all be proud."