With an ever-expanding list of Lions seeking pastures new in France, most notably Wales' James Hook, Lee Byrne and Gavin Henson in recent weeks, the news is a major boost to Irish rugby on the eve of their RBS 6Nations showdown with Italy and their province Leinster.
"Being of genuine Leinster stock it's great to have three such pivotal players join with a number of other players who have recently extended their contracts, reaffirming that loyalty amongst Irish players can still outweigh lucrative overseas offers," said a delighted Leinster coach Joe Schmidt.
But keeping Leinster's holy trinity on Emerald Isle has come at a cost - reputedly a combined annual salary of 1.2m Euros.
Lion king O'Driscoll has signed a one-year extension which will see him remain in Ireland until the end of the 2012-13 season while Heaslip's three-year deal and Sexton's two-year deal see the pair remain until June 2014.
"We haven't busted our budget," declared IRFU chief executive Philip Browne. "We know that the market is buoyant and players have to explore their options. They have done that but we have managed to get their signatures."
Ireland kick-off their championship campaign in Rome tomorrow with both O'Driscoll and Sexton in the starting XV. But Ireland will be without Heaslip, who is currently sidelined.