Rob Walton (net worth: $34.8 billion)

Born in 1944, Rob Walton is the eldest son of Sam Walton, founder of Wal-Mart. A keen collector of vintage cars and racing car driver, Rob Walton has been the chairman of Wal-Mart since his father’s death in 1992. A holder of a bachelor’s degree in business administrative from the University of Arkansas, he is married and has three children.