Terms of the deal weren't disclosed, per team policy.
Crabbe, the reigning PAC-12 player of the year, was acquired via a draft-night deal after Cleveland selected him with the 31st pick. The Trail Blazers gave up two future second-rounders in exchange for the athletic wing, who averaged 18.4 points and 6.1 rebounds throughout his junior season at California.
Crabbe should bolster an already strong backcourt featuring last year's Rookie of the Year, Damian Lillard, and this year's first-round pick, C.J. McCollum, a guard cut in the same mold as Lillard.
Crabbe, who'll wear No. 23 for the Blazers, drained 209 3-pointers over his three-year career with the Bears, which ranks third in school history.