The Glagolitic Mass (in Czech Mše hlaholská) is choral piece by Leoš Janáček. The text is written in Old Church Slavonic. The first performance was in Prague on 26 June 1926.

The term "Glagolitic" refers to the Glagolitic alphabet, the earliest alphabet used by the Slavs. Janáček was a strong supporter of pan-Slavism, and this mass has been viewed as a celebration of Slavic culture. It is also, unsurprisingly, connected to Kamila Stösslová, Janáček's great love.

The composer had extensive experience working with choirs, as well as writing a large amount of choral music, and this work is his masterpiece in that genre. It begins and closes with triumphant fanfares dominated by the brass. In between these sections lies particularly vibrant and rhythmic writing for voices (soloists as well as choir). Before the closing Intrada Janáček placed a difficult and wild organ solo. The Glagolitic Mass remains frequently performed and recorded today.