Wilcox drained seven 3-pointers en route to the career-high performance as the Huskies (11-6, 3-1 Pac-12) reeled off a fifth victory in six games overall.
Andrew Andrews chipped in 14 points and Mike Anderson grabbed 10 rebounds for Washington.
The defeat was especially costly for the Buffaloes (14-3, 3-1), who lost leading scorer Spencer Dinwiddie to what appeared to be left knee injury late in the first half.
He had to assisted off the court and didn't return.
Josh Scott netted 15 points and Wesley Gordon contributed 11 with 13 rebounds.