Flemming Weis was an organist and a composer. He studied at the Royal Academy of Music in Copenhagen and in Leipzig (with Karl Straube and Paul Graener). From 1926 he was a member of the board of the Danish section of the ISCM. In addition to that, he was a music critic. He was on the board of the Danish Composers' Society from 1956, and from 1967 he was its chairman. He was also Chairman of the board of the Society for the Publication of Danish Music. His works include orchestral and chamber compositions, piano works and instrumental works, songs, and choral works.