The Field Mass, H. 279, is a Czech language cantata from 1939 by Bohuslav Martinů. It was written to honor Czech volunteers fighting in the French army. The libretto does not follow a traditional mass text but a free libretto written by Jiří Mucha based on Psalm texts and liturgical texts. The work is written for a baritone singer, male chorus, wind instruments, piano, harmonium and percussion.