Wales Williams won Welsh caps at U18 level from Coleg y Cymoedd and then made 18 appearances at U20 level over two seasons. He made his Wales Sevens debut as a 19-year-old in the Japan leg of the
2013–14 IRB Sevens World Series and went on to play in tournaments on the Gold Coast, in South Africa, and Dubai. In May 2017, Williams was named in the Wales senior squad for the first time for the tests against
Tonga and
Samoa. He sat on the bench for the game against Samoa in Apia, but his international bow didn't come until a year later on the summer tour to the USA and Argentina when he scored a vital try in the 22–20 win over South Africa at the RFK Stadium in Washington DC. He was again on the score sheet when he was selected for his next start in the 2018 autumn triumph over Tonga and he claimed another try on his Six Nations debut as Wales battled back to beat France in Paris on 1 February 2019. He was injured during the match and did not make any further appearances during the tournament. In September 2019, Williams was selected as part of the Wales squad for the 2019 World Cup. He replaced Gareth Davies in the first pool game against Georgia and scored his first World Cup try within 20 minutes of his introduction. Williams appeared in every Wales game from the bench, scoring a further try in the final pool game against Uruguay. In January 2024, Williams was selected for the
2024 Six Nations. He was a substitute for the match against Scotland, and came on in the second half. He started the remaining four matches. Williams was selected for the
2025 Six Nations. He started all of Wales' matches. Williams was named in the squad for the
2025 end-of-year rugby union internationals. He started against
Argentina,
Japan and
New Zealand. Williams scored a try against Argentina. Williams was named in the squad for the
2026 Six Nations by
Steve Tandy.
British and Irish Lions On 8 May 2025, Williams was selected for the
British and Irish Lions for their
2025 tour to Australia during the summer. He scored two tries against the
Western Force before sustaining a hamstring injury ruling him out for the rest of the tour. == Personal life ==