As part of the contract, which is rumoured to be worth about £1.2m, Oliver will also work behind the scenes with the Sainsbury food development team.
Brand director Helen Buck said there was no better ambassador to promote Sainsbury's commitment to "offering customers healthy, fresh and tasty food at fair prices".
"He remains enormously popular with our customers and has forged a valuable working relationship with our fresh food development team, whom he consults with to challenge and inspire new standards of quality in Sainsbury products. We're looking forward to further building on the great work he does with us," Buck added.
Oliver, who began working with the supermarket in 2000, described the Sainsbury team as "passionate about bringing new and better products to customers, as well as continuing to champion British and organic produce".
Despite rumours last year that Sainsbury could drop Oliver from its ads, his contract renewal looked certain after the chef's recent school dinners campaign gained huge support from the public and press.