Hölderlin's Hymn "The Ister" is the title given to a lecture course delivered by German philosopher Martin Heidegger at the University of Freiburg in 1942. It was first published in 1984 as volume 53 of Heidegger's Gesamtausgabe. The translation by William McNeill and Julia Davis was published in 1996 by Indiana University Press. Der Ister is a poem by Friedrich Hölderlin, the title of which refers to an ancient name for a part of the Danube River.

Martin Heidegger was a German philosopher who is best known for contributions to phenomenology, hermeneutics, and existentialism. He is often considered to be among the most important and influential philosophers of the 20th century.