Castle Rackrent, a short novel by Maria Edgeworth published in 1800, is often regarded as the first historical novel, the first regional novel in English, the first Anglo-Irish novel, the first Big House novel and the first saga novel.

It is also widely regarded as the first novel to use the device of a narrator who is both unreliable and an observer of, rather than a player in, the actions he chronicles. Kirkpatrick suggests that it "both borrows from and originates a variety of literary genres and subgenres without neatly fitting into any one of them". William Butler Yeats pronounced Castle Rackrent "one of the most inspired chronicles written in English".

Shortly before its publication, an introduction, glossary and footnotes, written in the voice of an English narrator, were added to the original text to blunt the negative impact the Edgeworths feared the book might have on English enthusiasm for the Act of Union 1800.

The novel is one of the few of Edgeworth's novels which her father did not 'edit'.
The novel is set prior to the Constitution of 1782 and tells the story of four generations of Rackrent heirs through their steward, Thady Quirk. The heirs are: the dissipated spendthrift Sir Patrick O'Shaughlin, the litigious Sir Murtagh Rackrent, the cruel husband and gambling absentee Sir Kit Rackrent, and the generous but improvident Sir Condy Rackrent. Their sequential mismanagement of the estate is resolved through the machinations—and to the benefit—of the narrator's astute son, Jason Quirk.