Costello playing for Leinster against Bourgoin earlier in the season
ERC Elite award winning Victor Costello has announced his intention to retire from competitive rugby at the end of the season.
The Leinster and former Ireland back-row forward has made 56 Heineken Cup appearances in his 121 games for Leinster, as well as earning 39 caps for his country.
"Victor enjoyed an incredible sporting career and rugby played a huge part," said Irish coach Eddie O'Sullivan.
"He was one of the most talented athletes in world rugby and played a big part in the recent success of the national team."
Costello, whose father Paddy won a lone international cap against France 45 years ago, made his Irish debut against the USA in 1996.
The Dubliner had a short spell with Connacht and then London Irish in 1996, before returning home to carve out a wonderful career with Leinster and is the province's second-most capped player behind hooker Shane Byrne.
Chief Executive Mick Dawson also paid tribute to the Leinster stalwart.
"Victor Costello is one of the true legends of Irish sport. His place in Leinster folklore was confirmed when he earned both his 100th provincial and his 50th Heineken Cup caps last year.''
Costello is also an Irish athletics champion having represented Ireland in the shot putt at the 1992 Barcelona Olympics.