Sainsbury, who trained as a chartered accountant, was born in 1930 and joined the family business in 1956 in the finance department. In 1959 he rose to join his brothers Sir Timothy and Lord John as a company director.
He was widely credited as being the architect of Sainsbury's successful stock market listing in July 1973. Within one minute of opening, the list of applications for shares had been closed and£495 million had been offered for the 14.5 million available.
A Sainsbury spokeswoman said: 'The company was saddened to hear that The Hon. Simon Sainsbury passed away last week. He worked for Sainsbury's from 1956 to 1979 and was deputy chairman from 1969 to 1979. He made an enormous contribution to the company's outstanding growth and development during that time.'
On stepping down from his post as deputy chairman in 1979, Sainsbury began to pursue his charitable and philanthropic interests much more vigorously - principally through The Monument Trust.
The charity provides funding for the development of services for HIV and AIDs treatment and became extensively involved in helping rehabilitate the Meadow Well area of North Tyneside following riots there in 1991.