Fitzgerald, 25, has played 108 times for the province to date (scoring 26 tries) and was a key member of Leinster's League (2007/08) and three Heineken Cup successes (in 2009, 2011 and 2012).
He made his debut for Leinster at the age of 19 and the versatile former Blackrock College back featured in Ireland's recent Six Nations campaign and was selected for the 2009 British & Irish Lions tour to South Africa. To date he has made 26 international appearances.
Commenting on the news of his contract extension Luke Fitzgerald said: "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."
Leinster Coach Joe Schmidt added: "We are delighted that a player of Luke's ability has committed his future to the province. At just 25, his best years are ahead of him and hopefully he'll be back better than ever early next season."
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland