Mayer's wife, Geraldine, said he died of old age Monday age at Hospice Care in Fitchburg.
He was the third Oscar Mayer in the family that founded Oscar Mayer Foods, which was once the largest private employer in Madison. His grandfather, Oscar F. Mayer, died in 1955 and his father, Oscar G. Mayer Sr., died in 1965.
Mayer retired as chairman of the board in 1977 at age 62 soon after the company recorded its first $1 billion year. The company was later sold to General Foods and is now a business unit of Kraft.
Mayer's first wife, Rosalie, died in 1998. He married Geraldine Fitzpatrick in 1999.
Public visitations are scheduled from 4 to 7 p.m. Thursday and Friday at Cress Funeral Home for Mayer, who died Monday at Hospice Care in nearby Fitchburg.