[5] Mitchell scored two tries in their 2023–24 European Rugby Champions Cup quarter-final victory over Bulls and then started in the semi-final elimination against Leinster.

[9] Mitchell received his first call-up to the England under-20 team in October 2015[3] and was a member of the side that completed the grand slam during the 2017 Six Nations Under 20s Championship.

[18] In October 2021 Mitchell was called up to the England squad for their 2021 Autumn Nations Series match against Tonga, replacing the injured Harry Randall.

[21] Later that year he was initially not included in the squad for the 2023 Rugby World Cup however an injury to Jack van Poortvliet led to his selection.

[23] In the knockout phase he started the quarter-final victory over Fiji and semi-final elimination against champions South Africa as England finished third with the bronze medal.