The Irishman will join fellow double Open champion Ernie Els, as well as other Claret Jug winners in Sandy Lyle, Darren Clarke and Tom Lehman in the event on the Kings’s Course from 21-24 July.
"I am excited to be making my debut at The Senior Open and to be able to do so in Scotland is very special,” said Harrngton, who was one of Paul McGinley’s vice-captains for the 2014 Ryder Cup at the Pertshire venue.
“I always love playing there and it holds precious memories for me as the country of my first major championship win (ar Carnoustie in 2007).
“It will be a pleasure to be back at Gleneagles. It is a great venue and I have fond memories of being there as a vice captain at the 2014 Ryder Cup.”
The event is being held at Gleneagles for the first time and is set to rekindle memories of the Bell’s Scottish Open from its spell there.
“My earliest memory of the King’s Course was when watching Peter O’Malley make two eagles and three birdies in the last five holes of the final round to win the 1992 Scottish Open in a dramatic finish,” added Harrington.
Ticket prices for The 2022 Senior Open Presented by Rolex start at £20 on the Wednesday practice day.
Season tickets offering access to all four championship days at Gleneagles plus the practice day are priced at £110.