Shelley appears in Frankenstein Unbound by Brian Aldiss. The book is a time travel romance featuring Mary Shelley. There was also a movie made, based on the novel, directed by Roger Corman and starring John Hurt and Bridget Fonda, in 1990.
Shelley also features prominently in The Stress of Her Regard, a 1989 novel by Tim Powers which proposes a secret history connecting the English Romantic writers with the mythology of vampires and lamia.
He makes an appearance in the alternative history novel The Difference Engine by William Gibson and Bruce Sterling. Only referenced in passing by another character, in this world he does not drown in Italy, but lives to become a fierce critic (and perhaps saboteur) of Lord Byron's pro-industrial 'Radical party' government, for which he is arrested, declared insane, and placed in a madhouse.
Events in Shelley's and Byron's relationship at the house on Lake Geneva in 1816 have been fictionalized in film three times. (1) A 1986 British production, Gothic, directed by Ken Russell, and starring Gabriel Byrne, Julian Sands, and Natasha Richardson (2) A 1988 Spanish production, Rowing with the Wind (Remando al viento), starring Lizzie McInnerny as Mary Shelley,Hugh Grant and Elizabeth Hurley Both these movies deal mostly with Mary Shelley's creation of the Frankenstein novel, while Percy tends to be quite a minor character in both films.
Shelley is, however, the main character in a movie entitled Haunted Summer, made in 1988, starring Laura Dern and Eric Stoltz. It is set in the same time frame as Rowing with the Wind. Though somewhat sensationalistic in some scenes, Haunted Summer's impressive strength is its three-dimensional characterization of Shelley, Mary Shelley and Lord Byron. The psychology of these three is quite accurate, realistic and vivid, and the movie uses words for its dialogue that the three actually said during their lives. The movie also does a good job of recreating Switzerland in 1816, where the four exiles lived.
Howard Brenton's play, Bloody Poetry, first performed at the Haymarket Theater in Leicester in 1984, concerns itself with the complex relationships and rivalries between Shelley, Mary Shelley, Claire Clairmont, and Byron.
Shelley is also the main character in Bulgarian poet Pencho Slaveykov's philosophical poem, Heart of Hearts.
Mary and Percy Shelley also appears in a 2006 novel AngelMonster, by Veronica Bennet. This book is a fictional version of Mary's and Percy's elopement and the series of depressing events.
Percy, Mary and her sister Claire are some of the main characters in the novel, The Vampyre: The Secret History of Lord Byron, by Tom Holland (1995). The story concerns Lord Byron, poet and friend of Percy Shelley. Their meeting and the growth of their friendship are described, along with a hypothetical account of the time the foursome shared in Switzerland. Holland provides a fictional conclusion to the mysteries that surround Shelley's death.
Shelley's cremation at Viareggio and the removal of his heart by Trelawny are described in Tennessee Williams' play Camino Real by a fictionalized Lord Byron.