Joe Schmidt will take charge of his final Six Nations campaign next year, with Andy Farrell set to step up as Ireland head coach.
He will guide his side up until the World Cup in Japan in September before leaving to focus on family commitments.
The New Zealander led Ireland to a third Grand Slam last year, having also enjoyed two victorious campaigns since he took over in 2013.
Schmidt, 53, oversaw a first series win in Australia last summer and 2016 yielded a seismic win over the All Blacks, as well as a first win on South African soil.
He said: “I have decided to finish coaching and will prioritise family commitments after the Rugby World Cup in 2019.
“I feel that Irish rugby is in good hands. The management and players have been incredible to work with and the tremendous support we have had, particularly at home in the Aviva, but where ever we have travelled has been uplifting.
“Thank you to the IRFU for their support and patience and thanks also to so many people who have adopted my family and me, making us feel part of the community here in Ireland.
“There are some inspiring challenges over the next 11 months so there’s plenty of motivation for me to continue working hard, alongside the other management staff, so that the team can be as competitive as possible.”
Schmidt’s golden spell has included a 12-game unbeaten run across 2016/17 and 2017/18 and a record 12-game ongoing unbeaten stretch at home from November 2016.
Last night he was crowned World Rugby Coach of the Year for 2018 and Ireland were named World Rugby Team of the Year.
Philip Browne, chief executive of the IRFU, said: “Of course, this is not yet the end, and we look forward an exciting and challenging 11 months for Irish Rugby during Joe’s final Six Nations and the Rugby World Cup in Japan.
“On a personal level, I would like to thank Joe for his warmth, his time, honesty and his genuine interest in everything that we do in Irish Rugby to grow the game.”
Defensive guru Farrell joined the Ireland coaching staff in 2016 and has become a crucial part of Schmidt’s backroom team.
Before joining Ireland, he had coached with England and Saracens in Premiership Rugby as well as on the two most recent Lions tours, producing a series win in Australia and a draw in New Zealand.
Farrell said: “It is a privilege to be considered for such a prestigious role.
“I have learned a lot from Joe over the past few seasons and I will continue to learn from him over the next year as the coaching group and players focus on competing in two huge tournaments in 2019.”
Schmidt added: “The coaches have been fantastic to work with and Andy has made a big impact since coming into the group.
“His ability to lead and his understanding of the game will ensure that the group will continue to move forward.”
Farrell will lead the coaching team through the next World Cup cycle to the tournament in France in 2023.
David Nucifora, IRFU high performance director, said: “We are incredibly fortunate to have a coach of the calibre of Andy Farrell in Irish Rugby.
“He has proven through his work ethic and success with Ireland and the Lions over the last number of years that he is the person to take Irish Rugby forward after RWC 2019.
“The close working relationship that our current coaching group have and what they will continue to gain over the next year with Joe still at the helm leaves Andy and Irish Rugby in the enviable position of having continuity before building the road forward.”