Janko Kos (born 9 March 1931) is a Slovenian literary historian, theoretician, and critic.
Among Kos' closest collaborators during this time were the literary theoretician Taras Kermauner, dissident sociologist Jože Pučnik, writer Dominik Smole, essayist Primož Kozak, and the poet Dane Zajc, Kos' cousin.
Kos dedicated most of his scholarly career researching the literary, intellectual and personal profile of the Slovene Romantic poet France Prešeren, publishing several innovative studies in this regard.
Since 2004 he has been a member of the liberal conservative civic platform Rally for the Republic (Slovene: Zbor za republiko).
He is the father of the literary critic Matevž Kos and the father-in-law of the writer and editor Igor Bratož.