Clark has established himself in the Villa first-team squad this season and played 78 minutes of the recent home clash with Chelsea.
The defender, whose new deal lasts until 2014, said: "I'm delighted to sign a new deal and commit my future to the club.
"I feel I'm at a football club that is progressing and provides an environment in which the young players coming through all want to excel.
"The likes of Marc Albrighton, Barry Bannan, Nathan Delfouneso, Eric Lichaj and myself have all come through together and this underlines the quality of the youth structure at the club.
"It's a great feeling for me to be signing a new deal because it's what I've worked for since I first came here - to be a part of the team and to contribute what I can to a great football club."
Clark started at the heart of defence in the opening game of the season, a 3-0 victory over West Ham, and also featured in the Carling Cup victories over Blackburn and Burnley.
Clark added: "I know that the gaffer (Gerard Houllier) wants to see me continuing to improve and I'm looking forward to working hard over the next few years.
"I feel at home at the club and it would be fantastic to be a part of the success which all the lads here are striving for."