Brown chose the Wildcats over a long list of schools that included San Diego State, Texas Tech, Arkansas, and in-state options Washington and Washington State.
"The coaching staff was honest with me the first time we talked on the phone," Brown said. "The relationship we built kept getting stronger and stronger, and I think we can continue to build it."
Brown earned first-team All-WAC honors last season after averaging 20.7 points, 6.2 rebounds and 4.9 assists per game. He was a second-team All-WAC selection in 2018-19. Brown hit the 30-point mark on four separate occasions last season, including a 31-point, 10-assist outing in February against Grand Canyon.
Coach Sean Miller will count on Brown to replace Nico Mannion, who is expected to leave for the NBA draft.
"Nico is a good player," Brown said. "His transition into the NBA is proof-positive he dominated to the best of his ability every chance he got. And my job is to enhance the program even further to the best of my ability."
Brown is the third transfer who will be eligible for Arizona next season, following former Georgetown guard James Akinjo, who committed over the winter, and former Nevada big man Jordan Brown, who sat out the 2019-20 season.
Arizona is still in the mix for unsigned top-10 senior Ziaire Williams.