Alexander Mackendrick (September 8, 1912 – December 22, 1993) was an American-born Scottish film director and screenwriter. He directed nine feature films between 1949 and 1967, before retiring from filmmaking to become an influential professor at the California Institute of the Arts.

Born to Scottish immigrant parents in Boston, he was raised in Glasgow from the age of six. He began making television commercials before moving into post-production editing and directing films, most notably for Ealing Studios where his films include Whisky Galore! (1949), The Man in the White Suit (1951) - which earned him an Oscar nomination for Best Screenplay, The Maggie (1954), and The Ladykillers (1955).

In 1957, Mackendrick directed his first American film Sweet Smell of Success, which was a critical success, but a commercial failure . His directing career declined throughout the following decade, and he was fired or replaced from several projects, owing in part to his perfectionist approach to filmmaking.

Mackendrick retired from directing in the late 1960s after completing A High Wind in Jamaica (1965) and Don't Make Waves (1967), becoming the founding Dean (and later a Professor) of the CalArts School of Film/Video.

He was born on September 8, 1912, the only child of Francis and Martha Mackendrick who had emigrated to the United States from Glasgow in 1911. His father was a ship builder and a civil engineer. When Mackendrick was six, his father died of influenza as a result of the influenza pandemic that swept the world just after World War I. His mother, in desperate need of work, decided to become a dress designer. In order to pursue that decision, it was necessary for Martha MacKendrick to hand her only son over to his grandfather, who took young MacKendrick back to Scotland in early 1919 when he was six years old. Mackendrick never saw or heard from his mother again.

Mackendrick had a sad and lonely childhood. He attended Hillhead High School in Glasgow from 1919 to 1926 and then went on to spend three years at the Glasgow School of Art. In the early 1930s, MacKendrick moved to London to work as an art director for the advertising firm J. Walter Thompson. Between 1936 and 1938, Mackendrick scripted five cinema commercials. He later reflected that his work in the advertising industry was invaluable, in spite of his extreme dislike of the industry itself. MacKendrick wrote his first film script with his cousin and close friend, Roger MacDougall. It was bought by Associated British and later released, after script revisions, as Midnight Menace (1937).

At the start of the Second World War, Mackendrick was employed by the Ministry of Information making British propaganda films. In 1942, he went to Algiers and then to Italy, working with the British Army's Psychological Warfare Division. He then shot newsreels, documentaries, made leaflets, and did radio news. In 1943, he became the director of the film unit and approved the production of Roberto Rossellini's early neorealist film, Rome, Open City (1945).

After the war, Mackendrick and Roger MacDougall set up Merlin Productions, where they produced documentaries for the Ministry of Information. Merlin Productions soon proved financially unviable. In 1946 Mackendrick joined Ealing Studios, originally as a scriptwriter and production designer, where he worked for nine years and directed five films made at Ealing; Whisky Galore! (US: Tight Little Island, 1949), The Man in the White Suit (1951), Mandy (1952), The Maggie (US: High and Dry, 1954) and The Ladykillers (1955), the first two and the last being among the best known of Ealing's films.