The American keeper had his work permit approved this week.
"Just from seeing the facilities and the vision the club has with Randy Lerner, I figure the future is so bright," the former Chivas USA star told Villa's official website.
"I'm joining a talented group of young guys. It’s going to be training filled with competition day in and day out."
"I am going to go in there and work as hard as I can, learn as much as I can and try to become a better player and help the team in any way I can," Guzan added.
"Whether that is as a No 2 or competing for No 1, I am going to be pushing to make myself better or pushing the person who is playing to play better.
"Clubs with a good atmosphere have positive effects as they have competitive players who are pushing each other to make the team better."