Senderos was released by Fulham at the end of last season having spent the second half of 2013-14 on loan at La Liga outfit Valencia.
The 29-year-old struggled to make an impact at Craven Cottage but was part of the Valencia team that reached the UEFA Europa League semi-finals, only to be beaten by eventual winners Sevilla.
Following the end of his contract, Villa have moved quickly to sign the Swiss before he heads to the FIFA World Cup.
And Villa manager Paul Lambert is looking forward to pairing the former Arsenal man with captain Ron Vlaar at the heart of his defence.
"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," Lambert told Villa's official website.
"He has a good, strong mentality for the game, he'll be a great addition to the group."
Senderos, meanwhile, is looking forward to his third spell in the Premier League, and hopes to help Villa avoid being involved in the relegation battle next season.
"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.
"This is a team and a club which wants to do better, I know this, and hopefully we can all develop together and create something special.
"My goal is to help the team keep as many clean sheets as we can and to help drive Villa where we deserve to be and want to be."
