Marius Barnard (3 November 1927 – 14 November 2014) was a South African cardiac surgeon. He was the inventor of critical illness insurance. Barnard was a member of the South African parliament between 1980 and 1989. Barnard was born in Beaufort West, Western Cape. His brother was Christiaan Barnard.
Barnard died in Johannesburg, aged 87.