The county fought off bids from Edinburgh and Florence to bring the cycling event back to Britain for the first time since 2007, when London hosted a prologue won by Fabian Cancellara.
Organisers ASO there would be three stages in Britain, with one finishing in London.
"After an exceptional year for British cycling, marked by Bradley Wiggins's historic win in the Tour de France, the United Kingdom will again be honoured in 2014," an ASO statement said. "The Grand Départ of the 101st Tour de France will be on the 5th July in Leeds in the county of Yorkshire."
Gary Verity, chief executive of Welcome to Yorkshire, said: "It will mean less than two years after hosting the Olympics the British public can look forward to another of the world's biggest sporting events coming to the country.
"I am in no doubt they will come to Yorkshire in their millions, lining the length and breadth of the route to cheer on the champions of world cycling and our home grown British heroes."
The Grand Depart has already taken place abroad 19 times, including five in the Netherlands and four in Belgium.
More details will be revealed on 17 January at a joint press conference in Leeds and Paris.