Walter Kollo (28 January 1878 – 30 September 1940) was a German composer of operettas, Possen mit Gesang, and Singspiele as well as popular songs. He was also a conductor and a music publisher. Kollo was born in Neidenburg, East Prussia. His best known work, the operetta (1913), was the basis of a 1917 Sigmund Romberg operetta in America entitled Maytime. With Jean Gilbert and Paul Lincke, Kollo was a founder of the . His son was also a composer of light music and his grandson is the celebrated Wagnerian tenor René Kollo. Walter Kollo died in Berlin.