Peter Egan's first stage performance was in 'Charlie Girl'. Peter Egan's first television role was as the sex-and-cinema-obsessed Seth Starkadder in a BBC serialisation of Cold Comfort Farm (1968). In 1969 he had come to notoriety as the acid-throwing gangster Hogarth in the controversial Granada TV series Big Breadwinner Hog. Later he had other starring roles as John Everett Millais in the BBC serial The Love School (1975), and as Oscar Wilde in the serial Lillie (1978), starring Francesca Annis as Lillie Langtry; as Magnus Pym in the BBC dramatisation of John le Carré's A Perfect Spy (1987) and another BBC sitcom, Joint Account (1989–90).
He played the title role in the BBC series Prince Regent (1979), and was a sinister immortal Knight Templar in Michael J. Bird's BBC series The Dark Side of the Sun (1983). Egan also played Fothergill in the TV series Reilly, Ace of Spies (1983). In 1986 he had the role of Henry Simcox in the television dramatization of John Mortimer's Paradise Postponed. In 1988 he narrated the Video 125 drivers eye view 1066DC, which was a cab ride in a Network Southeast class 411 4CEP EMU from Hastings to London. He also guest-starred in episodes of The Ruth Rendell Mysteries ("A New Lease of Death," 1991) and A Touch of Frost ("Private Lives," 1999).
Other roles have included the character Michael Cochrane in the programme The Ambassador (1998), and on film as the suave secret agent Meres in TV spin-off Callan (1974), and the Duke of Sutherland in Chariots of Fire (1981). In 2007 he took the role of Victor in the film Death at a Funeral. In 2009 Egan toured as lead Sir Hugo Latymer in Nikolai Foster's revival of Noël Coward's A Song at Twilight. He is the narrator for the US and UK versions of Forza Motorsport 3 and its sequel, Forza Motorsport 4. He also voiced the Witch Trial Judge in Professor Layton vs. Phoenix Wright: Ace Attorney.
Egan is a longtime animal lover and vegan. Starting in around 2010, he began to campaign publicly on behalf of animal rights and animal welfare.
In 2012 he played in Alan Bennett's People alongside Frances de la Tour at the National Theatre.
In August 2015, Egan was announced as patron of the science-based campaign For Life On Earth (FLOE), which fights against animal testing in the field of human medical research.
In January 2016, Egan participated in Veganuary, and has remained vegan.
