In 2000, despite having no previous acting experience, the twins skipped school to attend an open audition in Leeds. After about six auditions, the twins were cast as
Fred and George Weasley in the film ''
Harry Potter and the Philosopher's Stone''. In 2009, the twins appeared as brothers in the fifth episode of the third season of the TV series
Kingdom. In 2012, they starred in ''A Mind's Eye'', a short documentary film based on the philosophical ideas of
Plato. The twins have also been involved in the Harry Potter Exhibition. They were present during its 2009 opening in Chicago and later toured various cities and countries to promote it. Phelps guest-starred in one episode of British television drama
Silent Witness, which aired on 6 January 2015. In 2019, he starred in fantasy movie
Cadia: The World Within, and was also credited as associate producer on the project.
Podcast Phelps has collaborated with his brother on a podcast, which was launched on YouTube and various streaming services, including Spotify and iTunes. The first season, which premiered in 2017, featured James and Oliver discussing their previous travels. The second season of the podcast was released in 2020 during quarantine, and the twins interviewed guests and spoke about their personal lives. In 2021, they released a third season, titled "Normal Not Normal", on which they collaborated with Stabl production; this season is more structured and professionally edited compared to the previous season. In this season, they discuss what normal really is and if it even exists. They have interviewed celebrities including
Sasha Banks,
Tom Hopper, and
Mara Wilson, as well as their former costars, such as
Katie Leung,
Evanna Lynch, and
Alfred Enoch. ==Personal life and philanthropy==