He finished 11th in the F1 standings in his debut season, ninth in 2020 with his first podium, and sixth last season with four podiums and his first pole position.
"I love the people and feel at home at McLaren," said Norris. "I have grown up in this team and I'm part of this journey we're all on.
"Last season was another great step, both in my career and the team's performance, and I see and feel all the work, investment, and commitment for the team to be in a position to challenge for wins and titles in the future."
Team principal Andreas Seidl said the deal reflected McClaren's confidence in the future of their driver.
"Lando has shown impressive growth as a Formula 1 driver over the past four years and has been an instrumental part of the team's momentum and performance trajectory," he said.
"We are still on our journey to fight at the front and Lando is a key element of our plan, so to lock him into place, alongside Daniel (Ricciardo) and our senior leadership, gives us stability and continuity as we build towards our ultimate shared goal of world championships."
