Wainwright originally looked destined for a career in football having been on the books of both Cardiff City and Newport County during his teenage years.
[4] Wainwright made his debut for the Welsh national team on 10 June 2018 versus Argentina as a second-half replacement.
[6] He scored his debut international try, on 20 October 2019, as Wales' opening try in the 2019 Rugby World Cup quarter-final against France at the Oita stadium.
[7][8] Under new Welsh coach Wayne Pivac, Wainwright underwent a shift from blindside flanker to Number 8.
Wainwright continued to feature for Wales throughout the 2021 end-of-year rugby union internationals and 2022 Six Nations, primarily at Number 8 but also appearing on the blindside.