De Allende was named in South Africa's squad for the 2019 Rugby World Cup. South Africa went on to win the tournament, defeating England in the final. De Allende started in all three tests for South Africa during the 2021 British &amp; Irish Lions tour to South Africa, earning his 50th cap for the Springboks during their third test victory that sealed a series win for the home team, and garnering widespread praise for his performances during the series.