Jervis started his international career claiming bronze at the 2014 Commonwealth Games while representing Wales. At the
2018 Commonwealth Games, competing for Wales, he won the silver medal in the
men's 1500 metre freestyle event. In 2023 he won the two gold medals at the
2023 British Swimming Championships in the
800 metres freestyle and the
1500 metres freestyle. It was the third time he had won the 800 metres event and the fifth consecutive time that he had won the 1500 metres event. After winning the 1500 metres freestyle for the sixth time, at the
2024 Aquatics GB Swimming Championships, Jervis sealed his place at the
2024 Summer Olympics. At the 2024 Olympic Games in Paris, he participated in the
men's 1500 metre freestyle competition, where he was eliminated in the heats. == Personal life ==