The 27-year-old initially left Villa when his previous deal expired at the end of last season.
Following talks with new Villa boss Paul Lambert, Guzan has decided to sign a new three-year contract with the club.
“I’ve watched Brad and some of his games when he was in the team last year and he was excellent,” said Lambert.
“I know he’s always had that stigma of being the number two behind some really good goalkeepers here.
“But when you come back at the start of the season nobody knows what’s going to happen and it depends on whoever does well.
“Brad played very well the time he was in and maybe he found himself a bit unlucky to be back out.
“The club needs two or three good goalkeepers, so when Shay comes back from the Euros it will be a big bonus and we’ll see what happens.”
