"Ross is a terrific player and he will naturally slot straight in as hooker," said Lions head coach Ian McGeechan.
"I look forward to welcoming him into camp tonight.
"Jerry Flannery has had a terrific season and it is disappointing that after selection for the Lions his season should end with a pre-tour injury.
"Injuries are a part of the game and while very distressing for the affected player we as a squad have to accept them as a fact of life. It is a part of the game we play.
"We are focussed on moving forward, concentrating on the task at hand and the first match."
Ford, who made his international debut as a replacement against Australia in 2004 but had to wait until the final game of Scotland's 2007 Six Nations campaign for his first start, has currently made 30 appearances for his country.
The Edinburgh star becomes the fourth Scot to be named a 2009 Lion after national captain Mike Blair joined original selections Nathan Hines and Euan Murray in McGeechan's tour party.
Ford will now battle with England's Lee Mears and Welsh international Matthew Rees for the Lions No2 shirt, while Flannery has today undergone an operation on his injured elbow and will begin his rehabilitation immediately.
Flannery was the fourth player to be ruled out of the entirety of the tour, with scrum-half Tomas O'Leary, centre Tom Shanklin and flanker Alan Quinlan the others to have had their Lions dream ended prematurely.
Teenage wing Leigh Halfpenny is currently undergoing treatment on a thigh injury and will miss the early part of the tour, although he will fly out to South Africa once he is fit enough to play. His replacement will be named in due course.