Waltz War (German: Walzerkrieg) is a 1933 German musical comedy film directed by Ludwig Berger and starring Renate Müller, Willy Fritsch and Paul Hörbiger. It is loosely based on the rivalry between waltz composers Joseph Lanner and Johann Strauss I, as well as the life of the Austrian ballet dancer Katti Lanner (Joseph's daughter) who eventually settled in Victorian Britain. It is also known by the alternative title of The Battle of the Walzes.

The film was made by the largest German studio UFA and shot at the company's Babelsberg Studios in Berlin with sets designed by Robert Herlth and Walter Röhrig. A separate French-language version Court Waltzes was also directed by Berger.