Mark Helias (born October 1, 1950) is an American double bass player and composer born in New Brunswick, New Jersey. He started playing the double bass at the age of 20, and studied with Homer Mensch at Rutgers University from 1971 to 1974, then at Yale University's School of Music from 1974 to 1976. He teaches at Sarah Lawrence College, The New School, and SIM (School for Improvised Music).