| O Ewigkeit, du Donnerwort | |
|---|---|
| Lutheran hymn | |
 Johann Rist | |
| English | O Eternity, you word of thunder |
| Text | by Johann Rist |
| Language | German |
| Melody | by Johann Schop, adapted by Johann Crüger |
| Published | 1642 |
"O Ewigkeit, du Donnerwort" (O Eternity, you word of thunder) is a Lutheran hymn in German, with text by Johann Rist, first published in Lüneburg in 1642. It was translated into English in several versions. The hymn was used in cantata music, including Bach's first chorale cantata of his second cantata cycle, BWV 20.