England Under-21 star Delfouneso made 17 appearances for the club last season, scoring two goals.
He also spent a period on loan at Burnley and was a part of Stuart Pearce's squad at the European Under-21 Championships earlier in the summer.
The highly-rated 20-year-old could feature more heavily in the upcoming season given that Villa have released John Carew and sold Ashley Young to Manchester United.
Source: PA
Source: PA