The Primera Division outfit have been confirmed as the fourth team to participate in the season warm-up event and will line up against the Jambos at The Showgrounds on Thursday, July 25.
Hearts will then complete their stay in Northern Ireland with a second match on the Saturday against either hosts Crusaders or a Liverpool XI, who kick-off the tournament on the Wednesday evening.
The Gorgie side have already announced that boss Gary Locke will open his pre-season schedule by taking the team to Fife next month to take on Dunfermline and Raith Rovers.
The Jambos will line up against Scottish Cup-winning former manager Jim Jefferies and his Dunfermline side at East End Park on Saturday, July 13.
Hearts will then take on Raith at Stark's Park on Wednesday July, 17.