There were reports linking the 25-year-old wing with a switch to Munster but Leinster announced on Tuesday that the Ireland player had agreed a new deal.
Fitzgerald will miss the remainder of this season after suffering an anterior cruciate ligament injury in Ireland's final Six Nations game against Italy.
The wing was ruled out for much of 2012 because of a neck problem and also suffered a bad knee injury in 2009.
That knee injury ruled him from November 2009 to the following autumn.
However, Fitzgerald is expected to be fit for the start of next season and has agreed new terms with the three-time Heineken Cup winners.
"I'm delighted to commit my future here. It is hugely frustrating to miss the run-in to the campaign but I'm looking forward to beginning my rehab over the coming weeks and getting back in a blue shirt next season," said Fitzgerald.
Leinster coach Joe Schmidt added that he believed Fitzgerald's "best years are ahead of him".
Luke Fitzgerald has agreed a two-year contract extension with Leinster.