Mayer had retired in 1977 as chairman of the board of Oscar Mayer Foods, a company founded by his grandfather, Oscar F. Mayer, in Chicago in 1904, the Wisconsin State Journal reported Wednesday.
Mayer's grandfather purchased a slaughtering plant in Madison in 1919 and eventually moved the company headquarters to Wisconsin.
Mayer joined the family business in 1936 after leaving Harvard University for health reasons.
At one time, Oscar Mayer Foods was the largest private employer in Madison. It was sold to General Foods and is now a unit of Kraft Foods.
The State Journal said while Mayer may have had the most famous name in Madison, many local residents did not even know he was a real person because the company used a midget called "Little Oscar" as its spokesman.