Born 19 June 1957 in Watford, England, Treves is the eldest son of actor Frederick Treves and the great great nephew of Sir Frederick Treves, the surgeon who treated Joseph Merrick, the Elephant Man.
Educated at the King's College School in Wimbledon and Birkbeck, University of London, he trained as an actor at the National Youth Theatre and the Bristol Old Vic Theatre School.
As an actor, he has played at many of the leading regional theatres. He made his debut with the Royal Shakespeare Company at Stratford in 1983, and returned in 1986 to play Joey Percival in Shaw's Misalliance at the Barbican, in a cast that included Brian Cox. His association with Cox continued in 1995 when Cox cast him as Buckingham in his production of Richard III at the Open Air Theatre, Regent's Park.
Anthony Hopkins cast him as Willy Nilly in his 1992 production of Under Milk Wood, and Treves assisted Hopkins in several more film and theatre productions. He continues to work in theatre, most recently in the capacity of writer and director, including his 1999 play Bitter with a Twist.
He has acted in over one hundred radio productions for the BBC since his debut as Joseph Conrad's Lord Jim in 1985, and was a member of the Radio Drama Company from 1989 to 1991 and again in 2007/8. Much of his work has been with award-winning radio producer Dirk Maggs, including Independence Day UK, The Amazing Spider-Man, The Adventures of Superman, The Gemini Apes and most recently Boscobel and The Adventures of Sexton Blake.
Beginning in the 1980's, Treves has worked frequently as a voiceover artist for TV, commercials, films, and video games.