The company said in a statement Sunday that Ford died of pneumonia at his home in Grosse Pointe, Mich. He was the last surviving grandson of company founder Henry Ford.
Ford served as an employee and board member of the automaker for more than half of its 100-year history.
The youngest of Edsel B. Ford's four children, William Clay Ford Sr. was first elected to the Ford Motor board in June 1948.
The company said in a statement that he was instrumental in setting the design direction for the automaker's vehicles.
He bought the NFL franchise a half-century ago.
"My father was a great business leader and humanitarian who dedicated his life to the company and the community," William Clay Ford Jr., executive chairman of Ford Motor Co. and Lions vice chairman, said in a statement. "He also was a wonderful family man, a loving husband, father, grandfather and great-grandfather."
CEO Alan Mulally said in a statement that Ford had a profound impact on the company.
Ford was married to the former Martha Parke Firestone, an heiress to the Akron, Ohio, rubber fortune. Her grandfather, Harvey Firestone, was a close friend of Henry Ford. They had three daughters, a son, 14 grandchildren and two great-grandchildren.
Funeral services will be private, fittingly for a man who didn't let the public get to know him.