Villa are pleased to confirm that Kyle Walker has joined on loan from Tottenham Hotspur to the end of the season.
The England U21 defender arrived at Bodymoor Heath this morning before undergoing a medical and completing the formalities of his move.
"I'm excited about being here and proving that I'm good enough to play in the Premier League," he said.
"That's why Tottenham bought me from Sheffield United and that's what I'm keen to show here at Villa.
"This is a great opportunity for me and I'm looking forward to taking it. I know several of the players here from England U19s and England U21s - Nathan Delfouneso, Ciaran Clark and Marc Albrighton.
"In fact, I roomed with Ciaran when we played Lithuania and Portugal in qualifiers for the European U21 championship and I'm sure those lads will help me to settle in and enjoy my time at Villa.
"I'm really keen to contribute and compete and prove myself here."
Villa manager Gerard Houllier added: "We're pleased that Kyle will be with us until the end of the season.
"He is 20 years old, an attacking full-back and a very promising young player. He will be a valuable addition to our defence."
Walker will be available to play against his former club, Sheffield United, in the FA Cup third round on Saturday at Bramall Lane.
Walker joined Tottenham from Sheffield United, along with young defender Kyle Naughton, in July 2009.
The Sheffield-born defender was subsequently loaned back to the Blades to gain further first team experience for the 2009-10 campaign.
Walker made 28 appearances for the Blades during the first half of the season before being recalled from his loan in February 2010.
He then made his Spurs first team debut in the 2-0 Premier League victory over Portsmouth in March 2010 and soon won his first cap for England at U21 level, having previously represented his country at U19 level.
After impressing for the first team during this pre-season and establishing himself in the setup, Walker joined Championship side QPR on a one-month loan in September 2010, which was subsequently extended until January 2011.
Earlier on in his career, Walker progressed through the ranks at Sheffield United before making his debut in an FA Cup tie against Leyton Orient in January 2009.
He made seven appearances for Kevin Blackwell's side all in all during 2008-09, becoming the youngest player ever to represent Sheffield United at Wembley in their play-off final defeat against Burnley in May 2009.
Prior to this, Walker also featured nine times during a loan spell at League One Northampton Town at the end of 2008.