Karel Weis (13 February 1862, in Prague – 4 April 1944, in Prague) was a Czech composer and musicologist. Weis studied at the Prague Conservatory; amongst his teachers was Antonín Bennewitz. He also took private lessons with Zdeněk Fibich. He was for some years a violinist at the Prague National Theatre, and later conducted opera in Prague and Brno. He also acted as organist. Between 1928 and 1941, he published a fifteen volume collection of folk songs. Among his many compositions are eleven operas, (three in Czech, and eight, of which six are operettas, in German), five of which premiered at