Vermaelen arrived in north London in 2009 and enjoyed a stellar debut season before injuries restricted his appearances. The Belgian is close to returning to full training and Wenger welcomed his decision to commit his future to Arsenal.
"It is a privilege to play for Arsenal Football Club and many players understand that," said the manager on arsenal.com.
"On our side we are happy to extend his contract because he has shown he has the quality to play for us. He is a leader as well and he is a left-footed player, you do not find many of them. It is important to find a player in his position who has a good first pass with his left foot.
"He is versatile too, you could imagine him playing in midfield or left back in an emergency."