Williams-Goss, a 6-foot-3 point guard, chose the Bulldogs over UNLV, Providence and Ohio State.
"I feel that their track record of winning at a high level, developing players during their redshirt year and their up-tempo offense that includes a ton of ball screens is an overall good fit for me," Williams-Goss said.
Williams-Goss announced in early April that he was leaving Lorenzo Romar's program. He started every game this past season for the Huskies, averaging 15.6 points, 4.7 rebounds and 5.9 assists. Those numbers were good enough to garner second-team All-Pac-12 honors.
Williams-Goss will have two years of eligibility remaining after sitting out the 2015-16 season due to NCAA transfer regulations. Gonzaga could lose up to five players after next season, so Williams-Goss will be counted on as a key player immediately.