"Everyone at Arsenal is looking forward to Calum's continued contribution to the club," Arsenal said in a statement.
Chambers is currently sidelined with a hip injury and has made just one appearance for the Gunners this season. He joined Arsenal from Southampton in 2014 and said he remains determined to establish himself as a first-team regular.
"I know I'm still a young player and I want to have my best years playing for this football club," Chambers said on Twitter. "I want to win as many trophies with Arsenal as possible.
I'm going to repay the fans for the faith they've shown in me. Can't wait to get going again." Chambers has made 60 appearances for Arsenal and earned his first and only England cap during his debut season with the Gunners.
However, he found himself used mainly as a back-up during his second season before going out on loan last year.
Chambers was one of several Arsenal players whose contract was set to expire in 2019, along with the likes of Aaron Ramsey, Danny Welbeck and Theo Walcott.
With stars such as Alexis Sanchez and Mesut Ozil set to run down the final year of their contract this season, manager Arsene Wenger has said he's keen to avoid letting more players enter the final year of their deals without signing an extension.