The veteran, who is now 38, will serve as the training goalkeeper for coach Gareth Southgate.
Heaton is not expected to play any games and will instead support Jordan Pickford, Aaron Ramsdale and Dean Henderson.
"Incredibly honoured to be asked by Gareth to join the squad," Heaton wrote on X.
"To get the call to go to a major tournament, to help in anyway I can and pass on my experience, is a proud moment.
“We have a great squad, I’m excited and can't wait to join the group."
England manager Gareth Southgate stated: "Experience tells us that a tournament can put a lot of demand on our goalkeeping group.
"Tom will play an invaluable role on the training pitch supporting Jordan, Aaron and Dean.
"Off the field, as someone we all know well, he will add to the positive environment we are always looking to create."