The defender, who was out of contract at the end of the season, had been expected to sign fresh terms at the King Power Stadium and has now committed his future to the Foxes.
Leicester are third in the Premier League, four points behind leaders Liverpool, ahead of Sunday’s trip to Newcastle.
Evans told LCFC.com: “I’m absolutely delighted to have signed. I’m delighted to commit myself to the club, and delighted the club have committed themselves to me.
Three-time Premier League winner Evans joined the Foxes from West Brom for £3.5million in 2018.
The 32-year-old has made 89 appearances for the club, scoring three times.