Johann Olearius (17 September 1611 – 24 April 1684) was a German hymnwriter, preacher, and academic.
Olearius taught philosophy at his alma mater, the University of Wittenberg. He also served as a court preacher and chaplain. He compiled "one of the largest and most important German hymnals" of the 1600s. His hymn "Gelobet sei der Herr, mein Gott" is the base for the chorale cantata Gelobet sei der Herr, mein Gott, BWV 129, by Johann Sebastian Bach, who included another stanza in his cantatas Freue dich, erlöste Schar, BWV 30.
- "Johann Olearius". bach-cantatas. Retrieved 24 June 2013.