Headlong Hall is a novella by Thomas Love Peacock, his first long work of fiction, written in 1815 and published in 1816. As in his later novel Crotchet Castle, Peacock assembles a group of eccentrics, each with a single monomaniacal obsession, and derives humor and social satire from their various interactions and conversations. The setting is the country estate of Squire Harry Headlong Ap-Rhaiader, Esq., in Wales.

Thomas Love Peacock (18 October 1785 – 23 January 1866) was an English novelist, poet, and official of the East India Company. He was a close friend of Percy Bysshe Shelley and they influenced each other's work. Peacock wrote satirical novels, each with the same basic setting: characters at a table discussing and criticising the philosophical opinions of the day.