Knut Riisnæs (born 13 November 1945) is a Norwegian jazz musician (saxophone and flute), arranger, and composer, son of pianist Eline Nygaard Riisnæs and brother of classical pianist Anne Eline Riisnæs (1951–) and jazz saxophonist Odd Riisnæs (1953–). The brothers are both known from a variety of recordings in Norway and internationally.