Alibi is a 1931 British mystery detective film directed by Leslie S. Hiscott and starring Austin Trevor, Franklin Dyall, and Elizabeth Allan.The film was adapted from the 1928 play Alibi by Michael Morton which was in turn based on the 1926 Agatha Christie novel The Murder of Roger Ackroyd featuring her famous Belgian detective Hercule Poirot.

Austin Trevor once claimed he was cast as Poirot because he could speak with a French accent. It was the first of three Poirot adaptations made by Twickenham Film Studios in the 1930s, followed by Black Coffee the same year, and Lord Edgware Dies in 1934, all starring Trevor as Poirot. He later appeared in The Alphabet Murders, a 1965 Christie film, playing a minor role.

It is now considered to be a lost film.