The three players all leave the club after their contracts expired, as Villa let go of £12 million worth of talent.
Former England striker Heskey spent three years at Villa Park following his £3.5m move from Wigan Athletic, and went on to make 113 appearances for the Birmingham club.
However, the 34-year-old only managed 15 goals in that period, and has only found the net twice since the start of 2011.
Cuellar arrived at Villa from Rangers for £7.8m in 2007. His departure was widely expected, with the versatile defender getting an emotional send-off from the travelling fans at Carrow Road after Villa lost 2-0 at Norwich City on the final day of the season.
The Spaniard has already stated his desire to remain in England next season as he searches for a new club.
Academy players Ebby Nelson Addy, Connor Taylor, Charlie Ward, Reece Caira, Richard Bryan, Matthew Coton, Darious Darkin and Seb Jenkins have also been released.