The Castle of Otranto is a 1764 novel by Horace Walpole. It is generally regarded as the first gothic novel. In the second edition, Walpole applied the word 'Gothic' to the novel in the subtitle – "A Gothic Story". The novel merged medievalism and terror that has endured ever since. The aesthetics of the book shaped modern-day gothic books, films, art, music and the goth subculture.

The novel initiated a literary genre which would become extremely popular in the later 18th and early 19th century, with authors such as Clara Reeve, Ann Radcliffe, William Thomas Beckford, Matthew Lewis, Mary Shelley, Bram Stoker, Edgar Allan Poe, Robert Louis Stevenson and George du Maurier.