The ex-Norwich manager has been looking to bolster his side since arriving in June, and after conceding four goals in their opening two Premier League matches the Scot has added another defensive option to his ranks with the 22-year-old left-back.
Bennett made 92 appearances for Boro since graduating from their youth academy in 2008, and was an ever-present for the Championship club last season. He can operate anywhere on the left-hand side but is naturally a full-back and has shown enough to convince Lambert to offer him a four-year deal at Villa Park.
"Joe's a really good player, young and hungry to succeed and he's exactly the type of player we want here at the football club," Lambert told the club’s official website.
|GOALS WILL COME - LAMBERT
|16/1||Aston Villa are 16/1 with William Hill to beat Newcastle 2-1
"There's no doubt in my mind that he will thrive in this environment and he fits in exactly with what we are trying to build here.
"His energy level is really high and he can get up and down the pitch really well, which will be important for the team and important in terms of how we want to play as a team.
"He's an exciting signing for the club and I'm really pleased we've been able to take him here."
It is a meteoric rise for the defender given he has yet to make 100 first team appearances and only signed professional terms four years ago. However he has shined throughout his time with Middlesbrough and in 2010-11 he was voted the club's player of the year, but all he is thinking about now is performing well in the top flight for his new club.
"I am really excited to have joined a massive club in Aston Villa and I'm eager to fight for a starting place and get in the team," Bennett said.
"It was not long ago that I was given my professional debut at Middlesbrough by Gareth Southgate and it is a real privilege to now follow in his footsteps and join a club with Villa's heritage.
"When I first heard about the move a lot of things ran through my head. There was excitement and nerves and most of all a real buzz about the prospect of coming to Villa and playing in the Premier League.
"Now that it's come around so fast, I'm just raring to go. I've had a look around the stadium and the training ground and the facilities are top-class.
"My approach has always been to get forward and try to create things. In my opinion Ashley Cole and Gael Clichy are the best full backs around and if I keep working on my game and improving it I know I can succeed at this level and help the team.
"It's up to the manager to pick the team, of course, but it would be great to go back to the north east this weekend and make my debut against Newcastle at St James's Park.”