The 31-year-old’s previous deal was due to expire at the end of the season.
The midfielder has recently been linked with a number of clubs.
Rosicky told the club’s official website: “It’s a great honour to sign a new deal with Arsenal, I love the club and am proud to wear the Arsenal shirt.
“It’s felt like home since I arrived six years ago and I couldn’t be happier to commit my future to the team.
“The manager, my team-mates, the staff and the supporters – everyone plays their part in making this a great club, and I feel privileged to be a part of it.
“I believe we have a really talented group of players and, together with the manager, the future looks bright.
“It’s always been my goal to win trophies here at Arsenal, and I will fight hard to achieve my dreams here.”
Arsenal boss Arsene Wenger added: “I’ve always been a big admirer of Tomas’ abilities and am delighted he’s chosen to commit his future to the club.
“I believe he is an exceptional player, a natural footballer who is technically top class.
“He plays the style of football we champion here and shares completely our philosophy. He is always ready to work for the sake of the club, always willing to put the team first. I have huge respect for him.”
