Kostas Korsakas (5 October 1909 – 22 November 1986) was a Lithuanian and Soviet literary researcher, critic, philologist, poet and public figure.
Born in to a poor working-class family, Korsakas spent most of his childhood in Riga where his parents looked for work.
[2] In 1928, Korsakas was arrested alongside some fellow students who were interested in Marxism and was held in the Šiauliai prison [lt].
In criticism, he used sociologized methods of interpreting literary works, borrowed from Russian revolutionary democrats and Marxists (such as Vissarion Belinsky, Georgi Plekhanov, V. V. Vorovsky and V. M. Fritsche).
Kosakas also published several collections of poems - "Kovos įstatymas" ("The Law of Struggle", 1943), "Paukščiai grįžta" ("The Birds Return", 1945), "Pjūtis" (1969), "Lapkritys" (1979).