John Williams begins his professional career with the ThunderBolts in 2016. He signed with the team on June 12, 2016. The four-year player at UC Davis spent 2016 spring training with Southern Illinois. Williams hit his collegiate best .301 as a senior in 2015 with a .342 on-base percentage and 14 stolen bases. He also committed no errors while playing 55 games. His strong senior season earned him All-Big West Conference honorable mention. In four years with the Aggies, he batted .258, stole 26 bases and drove in 79 runs. Williams attended St. Francis High School in Mountain View, California.