Brian Leo "Jazz" Muller (11 June 1942 – 12 December 2019) was a New Zealand rugby union player. He played as a prop. He played for Taranaki at a provincial level from 1963 to 1972. He was a member of the New Zealand national side, the All Blacks, from 1967 to 1971. He played 35 matches for the All Blacks, including 14 internationals.