The deal is worth $4.8 million over three years, sources told The Athletic's Shams Charania.
After being selected 55th overall by Utah, Williams-Goss moved overseas and played two seasons in Europe, most recently with EuroLeague side Olympiacos. He averaged 11.3 points, 4.6 assists, and 2.5 rebounds across 23 games in the Greek Basket League last season.
In 2017-18, Williams-Goss played in nine EuroCup contests with Partizan NIS, averaging 17 points and 6.7 assists while shooting 50 percent from deep on 3.6 attempts per game. He also helped the club win the Serbian Cup that season.
The 24-year-old played two years in college with Washington before transferring to Gonzaga for his final collegiate season. He played with the Jazz's summer league team in 2017 prior to beginning his professional career in Serbia.