Peter de Jersey trained at the Central School of Speech and Drama. His first season at the Royal Shakespeare Company in 1991 was the result of a combination of people leaving the company either after the Newcastle run (Clarence Smith) or at the end of August (Ralph Fiennes and Linus Roache). This resulted in de Jersey taking over Smith's roles and replacing Paterson Joseph as Patroclus in Sam Mendes's production of Troilus and Cressida when Joseph took over for Ralph Fiennes as Troilus. Peter de Jersey subsequently took over for Linus Roache as the Duke of Aumerle in Richard II when it opened at the Barbican in September 1991. In 2008 while playing Oberon de Jersey also understudied the part now normally doubled with Oberon, Theseus.