Vier ernste Gesänge, Op. 121, is a cycle of four songs for bass and piano by Johannes Brahms. As in his Ein deutsches Requiem, the texts are compiled from the Luther Bible. Three songs deal with death and the transience of life, while the fourth has an outlook of faith, hope and charity. Brahms composed the work in Vienna in 1896 and dedicated it to Max Klinger. The songs were premiered there in the presence of the composer by baritone Anton Sistermans and pianist Coenraad V. Bos. They have been recorded often by both female and male singers.

Coenraad Valentijn Bos was a Dutch pianist, most notably as an accompanist to singers of lieder. His peers such as Gerald Moore considered him the doyen of accompanists in his day.