Ilmari Turja (28 October 1901 – 6 January 1998) was a Finnish writer, best known as a journalist and playwright, with a career spanning nearly eight decades from the 1920s to the 1990s.

Kaarlo Ilmari Turja was born to a farming family in Isokyrö in western central Finland, to Jaakko and Evelina Turja. However, when he was four, the Turja family moved to the nearby city of Vaasa, where his father set up in timber trade.

After graduating from secondary school in 1922 and completing his military service, Turja went on to study law at the University of Helsinki, obtaining his law degree in 1929 and qualifying as Varatuomari (Master of Laws with court training, cf. barrister) in 1932.

Turja is perhaps best known as the Editor-in-Chief of the weekly news and political commentary magazine Suomen Kuvalehti, which he led from 1936 to 1951. In addition to that, he also held the same post at two other weekly magazines, Kansan Kuvalehti (1929—1934) and Uusi Kuvalehti (1952—1963). Collectively, his career of running three notable and influential magazines over a period more than thirty years has been described as "unparalleled" in Finnish journalism.

Afterwards, Turja wrote columns for the Apu magazine for 27 years, into the early 1990s.

Turja has been credited with introducing investigative journalism to Finland, and promoting it throughout his career. He was also a known advocate of freedom of speech.

Turja's major literary works include:

Johannes Renko remains Turja's only novel. His editor at the time, Mika Waltari, is known to have been unimpressed by the quality of his prose, and actively encouraged Turja to become a dramatist instead.