In 2019 Williams revealed he had been diagnosed with testicular cancer, and would take time away from the game to undergo treatment.[4][5] He returned to professional rugby in January 2020.[6]
On 14 July 2020, Williams signed for Pro14 side Scarlets ahead of the 2020–21 season.[7]
In March 2019, Williams was named as a target of interest for incoming Wales coach Wayne Pivac,[9] after it was confirmed that Williams is qualified to play internationally for the country through his father, who is from Rhyl.[7] He also identifies as Welsh, like his father.[10]
In June 2019 Williams played for England in a non capped international 51–43 win against the Barbarians, scoring a try.[11]
Williams made his debut for Wales on the 18 November 2020 in the starting line-up for the 18–0 win against Georgia.[13] On 28 November 2020 in his second appearance for Wales he scored a try in the 24–13 defeat against England.[14]