Mario Serandrei (23 May 1907 – 17 April 1966) was an Italian film editor and screenwriter.
Born in Naples, he started in the film industry in 1931 as an assistant director. He edited over two hundred films during his career, and worked steadily until his death in 1966. As an editor, Serandrei's credits included Federico Fellini's Il bidone (1955), Pietro Francisci's Hercules (1958) and Hercules Unchained (1959), Valerio Zurlini's Estate violenta (1959), La ragazza con la valigia (1961) and Cronaca familiare (1962), and the Robert Aldrich/Sergio Leone film of Sodom and Gomorrah (1963). He enjoyed a long working relationship with director Luchino Visconti, editing Ossessione (1943), Bellissima (1951), Senso (1954), Rocco and His Brothers (1960) and The Leopard (1963).
At the end of his career, he edited many films directed by Mario Bava, including Black Sunday (1960) (which he also co-wrote), Black Sabbath (1963), and Blood and Black Lace (1965).