The 29-year-old, who is part of Switzerland’s squad for the World Cup in Brazil, becomes Villa manager Paul Lambert’s first signing of the summer.
"I'm really delighted to be joining Aston Villa, a great club with such a big history, and for me this is a great step in my career," he said.
"There will be a lot of competition for places with Ron Vlaar, Ciaran Clark, Nathan Baker and Jores Okore also very capable Premier League defenders, so it will be up to me to fight for and to earn my place in the team."
Lambert added: "He's played for some top sides and was a big influence in Arsenal's run to the Champions League final in 2006, so we're bringing in a really experienced player who's been there and done it and that will be important for the team."
- Sports & Recreation
- Aston Villa
- Ciaran Clark
- Jores Okore
- Premier League