Alistair Stuart MacLean (Scottish Gaelic: Alasdair MacGill-Eain; 21 April 1922 – 2 February 1987) was a Scottish novelist known for his thrillers and adventure stories. Many of his novels have been adapted into films, most notably The Guns of Navarone (1957) and Ice Station Zebra (1963). In the late 1960s, encouraged by film producer Elliott Kastner, MacLean began writing original screenplays concurrently with accompanying novels. The most successful was Where Eagles Dare (1968), which was also a bestselling novel.

MacLean also published two novels under the pseudonym Ian Stuart. His books are estimated to have sold over 150 million copies, making him one of the best-selling fiction authors of all time. According to one obituary, MacLean "never lost his love for the sea, his talent for portraying good Brits against bad Germans, or his penchant for high melodrama." Critics often criticized his cardboard characters and vapid females, but readers loved his combination of hot macho action, wartime commando sagas, and exotic settings that included Greek Islands and Alaskan oil fields.

Born as the son of a Scots Minister, MacLean was brought up in the Scottish Highlands. In 1941, at the age of eighteen, he joined the Royal Navy, and his experiences aboard a cruiser provided the background for HMS Ulysses, his first novel. After the war, he earned an English Honours degree at Glasgow University and became a schoolmaster. In 1983, he was awarded a D. Litt. from the same university.