The youngster, who recently turned 17, has signed a two-and-a-half year deal.

Forrester joined from Watford in July and a tribunal in December ruled that Villa would have to pay an initial �250,000 for the midfielder.

The Hornets will collect further payments when he makes his first-team debut for Villa and also on his first start for the full international side.

Watford will also benefit from a sell-on fee and the deal could eventually be worth �1.2m to them.

Villa Academy director Bryan Jones was delighted that Forrester had signed professional terms.

"Harry is a good passer, has great vision and can play in a variety of positions," he told the club's website.

"There's still a lot to learn. He will have to work hard, put in lots of effort and perform well for Aston Villa.