The announcement was made on his official website, ralphmcquarrie.com. The website did not give a cause of his death, only that he died on Saturday.
McQuarrie created conceptual designs for the film, some of which became Darth Vader, Chewbacca and the droids R2-D2 and C-3PO.
George Lucas, who directed "Star wars," says he often relied on McQuarrie's illustrations to explain concepts to other people.
McQuarrie created concept designs for many other films including "E.T." and "Close Encounters of the Third Kind." He also won an Oscar in 1985 for the visual effects in "Cocoon."