Dublin - Ireland flanker Sean O'Brien signed a new three-year contract with the Irish Rugby Football Union on Tuesday that will keep him at Leinster until after the 2019 World Cup.
O'Brien made his debut for the three-time European champions in 2008 and won the first of his 41 caps a year later and has made two Test appearances for the British and Irish Lions.
"Growing up as a young lad in Tullow it was always my ambition to play for Leinster and Ireland so you never take moments like this for granted," O'Brien said.
"I'm very grateful for the opportunity to sign with a club that I feel is going in the right direction.
"I think we have a hugely talented group of players and coaches at provincial and national level and it is something that I want to be a part of."
O'Brien has made 98 appearances for Leinster and starred for Ireland at this year's World Cup.
IRFU performance director David Nucifora added: "Sean is not only a proven world class player but he is a leader within the national set up and at Leinster.
"The IRFU is delighted that Sean has committed to playing in Ireland until after the next World Cup."