Local media reported the contract was worth $56.7 million, making it the richest deal ever for an NFL interior offensive lineman. The Saints did not release financial terms.
"Jahri is an excellent young player who has been part of the nucleus of this team since arriving in 2006 and we're excited to know that he's going to be with us for many years to come," general manager Mickey Loomis said in a release.
"We liked what we saw from him as a small-school prospect in the draft four years ago, and I can say that we've loved what we've seen from him on the NFL level as well."
Evans, 26, has started all 64 games since being drafted in 2006 out of Bloomsburg University in Pennsylvania.
(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Steve Ginsburg)