Mary Beatrice Klass (born 16 May 1935) is a Singaporean former sprinter. She competed in the women's 100 metres at the 1956 Summer Olympics. Klass won a silver medal in the 100 metres at the 1954 Asian Games. She is a Eurasian of Dutch and Portuguese descent. In 2016, Klass was inducted to the Singapore Women's Hall of Fame.