Richard "Rick" Castle is a fictional character portrayed by Nathan Fillion in the ABC crime series Castle.

Castle is an author of mystery fiction, with 26 bestsellers under his belt. His most popular works comprise a series starring "Derek Storm," including the novels Gathering Storm, Unholy Storm, Storm's Last Stand, Storm Season, Storm Rising, and Storm's Break; in the pilot episode, Castle attends a party for the release of the final book in the Storm series, Storm Fall, in which he kills off his protagonist after becoming bored with the character. He later reads from the novel before a book-signing. Patterson and Cannell both disagree with the decision, with Cannell claiming that he could have crippled Storm instead. Castle's other books include Death of a Prom Queen, Flowers For Your Grave, Hell Hath No Fury, A Skull at Springtime, At Dusk We Die, When it comes to Slaughter, and A Rose for Everafter.