Sébastien Japrisot (4 July 1931 – 4 March 2003) was a French author, screenwriter and film director.
His pseudonym was an anagram of Jean-Baptiste Rossi, his real name.
Renowned for subverting the rules of the crime genre, Japrisot broke down the established formulas "into their component pieces to re-combine them in original and paradoxical ways." Some critics argue that though Japrisot's work may lack the explicit experimental element present in the novels of some of his contemporaries, it shows influences of structuralist theories and the unorthodox techniques of the New Novelists.
He remains little known in the English-speaking world, though all his novels have been translated into English and all but one of them have been made into films.