Ian Mackintosh, MBE, (born July 26, 1940; disappeared and presumed dead July 1979) was a Scottish naval officer, a writer of thriller novels, and a screenwriter for British television.

His first novel, A Slaying in September, was published in 1967. He wrote four other original novels between 1967 and 1970; his later books were either based on his television series, or were novelizations of televised episodes of his television series.

Whilst serving as a Royal Navy officer, he co-created the popular and acclaimed BBC television series Warship (1973-1977) and wrote several of its episodes. It was set on board the fictional HMS Hero (F42), which was portrayed by the real Leander class frigate HMS Phoebe.

Employed at Yorkshire Television after Warship, he created and wrote most of the episodes of Wilde Alliance, Thundercloud, and The Sandbaggers.

In July 1979, Mackintosh was flying with two others (his friend Graham Barber, who was the pilot; and Mackintosh's girlfriend, Susan Insole) over the Gulf of Alaska in a light aircraft. The plane sent out a distress signal, which was picked up by the United States Coast Guard. The plane's last-known position was searched, but no wreckage of the plane was ever found, and its passengers have not been heard from since.