Undine is an opera, with spoken dialogue, in three acts by the German composer and author E. T. A. Hoffmann.

The libretto, by Friedrich de la Motte Fouqué, is based on his own story Undine.

Undine was Hoffmann's greatest operatic success and a major influence on the development of German Romantic opera.

Carl Maria von Weber's enthusiastic review of the opera admired it as "an art work complete in itself, in which partial contributions of the related and collaborating arts blend together, disappear, and, in disappearing, somehow form a new world".

There is a 1960 recording (including the spoken dialogue) by the Choir and Symphony Orchestra of the Bavarian Radio, conductor: Jan Koetsier, Undine: Rita Streich, Hulbrand von Ringstetten: Raimund Grumbach, Berthalda: Melitta Muszely, Kuhleborn: Karl-Christian Kohn, Ein alter Fischer: Max Proebstl, Seine Frau: Sunhild Rauschkolb, Heilmann: Kieth Engen, Herzog: Anton Rosner, Herzogin: Marjorie Heistermann; and a 3 CDs 1993 recording[2] (leaving out the spoken dialogue) by the Berlin Radio Symphony Orchestra and the Choir of St. Hedwig's Cathedral in Berlin, conductor: Roland Bader; Roland Hermann, Hans Franzen [de], Elisabeth Glauser, Krisztina Laki, Heikki Orama, Karl Ridderbusch, Ulrich Ress, Dora Koschak, Mani Mekler.