Wales forwards coach Robin McBryde will join Leinster's coaching staff after the World Cup in Japan later this year.
McBryde, who has been a key part of Wales boss Warren Gatland's support team, will fill the vacancy at Leinster created by John Fogarty's appointment as Ireland scrum coach.
Gatland, McBryde and attack coach Rob Howley will all leave their Wales posts following the World Cup.
Former front-row forward McBryde, who won 37 caps for Wales, has been part of a national coaching team that masterminded three Six Nations Grand Slams.
The 48-year-old said: "I am delighted to be joining Leinster. They are one of the stand-out teams in Europe, with a strong identity and a proud history.
"I see it as a great opportunity to join a very experienced and exciting coaching team, and to help continue Leinster's great successes.
"I am hugely proud of my time with Wales, and it has been an honour to coach my country."
Leinster head coach Leo Cullen added: "Robin McBryde is a coach and person I have admired for a long time as he went about his business with the Welsh national team, contributing to an unprecedented era of success during his 13-year involvement.
"He will bring a wealth of experience to Leinster after working so closely with, and against, many of the leading forwards in the game.
"We are delighted that Robin has agreed to join our coaching team after this year's World Cup, and I am really excited about getting the opportunity to work closely with him."
Current Scarlets boss Wayne Pivac will succeed Gatland after the World Cup, with his coaching staff to feature former Wales internationals Stephen Jones and Jonathan Humphreys.