Die Fledermaus () is an opera by Johann Strauss II. Its first performance took place on April 5, 1874 at the Theater an der Wien in Vienna, Austria. The opera has been presented on New Year's Eve in Vienna since the early 1930s. "Die Fledermaus" is based on the French play "Le Réveillon" (1872) by Meilhac and Halévy.