With a Mars Comes Great Responsibility. Work. Rest. Play. Mars Mars Incorporated is a worldwide manufacturer of confectionery, pet food and other food products. The company is entirely owned by the Mars family, making it one of the largest privately owned U.S. corporations. Mars is most famous for its eponymous Mars Bar, as well as other confectionery such as Milky Way, M&M's, Twix, Skittles and Snickers.