The football team began supporting the children's hospice more than two years ago and decided to take this relationship further for the 2008/20099 season after coming to the end of a two-year shirt deal with internet gambling operator 32Red.
The deal with 32Red was believed to be worth around £2m a year.
Aston Villa and Acorns will run a series of initiatives and events to promote the partnership on a local and national level to give the public the opportunity to learn about and support Acorns' work.
Villa said in a statement: "We regard this partnership as more important and more valuable than any commercial opportunity presented to us."
The Midlands club is the first Barclays Premier League team to enter into a non-profitmaking shirt deal.
However, the move follows that of Barcelona, which signed a five-year deal with Unicef in September 2006.