Announcing the news today, Oli Jager said: "It is with a very heavy heart that I share that I have been advised to medically retire from rugby.
"Playing professional rugby for the last 10 years has been nothing short of a privilege.
"I am incredibly grateful to everyone who has been part of my journey - my coaches, team-mates, medical and rugby staff, supporters, friends, and family. Each of you has helped shape me not only as a player, but as a person.
"While this chapter comes to an end, I look back with immense pride and gratitude for the experiences, memories, and relationships the game has given me.
"Who knows what the next chapter holds, but I'm excited to see what it has in store."
Munster head coach Clayton McMillan commented: "Oli is a hugely respected and popular member of our squad and he can take great pride in everything he has achieved in the game.
"I have a lot of admiration for how he earned his stripes as a rugby player, taking a chance as a teenager and moving across the world to New Zealand.
"It's an amazing story really, how he earned a contract at one of the biggest club sides in the world at Crusaders and played such a key role in their success.
"He has made a big contribution to Munster Rugby as a player and a person, and is extremely highly-regarded by team-mates, staff, and supporters alike.
"It's every player’s dream to represent their country and to have earned a cap with Ireland is something I'm sure he will look back on very fondly.
"I know he will enjoy great success with whatever he chooses to do next in life, and we wish him and his family the very best."
Born in London, Jager started out at Naas RFC before playing schools rugby at Newbridge College and Blackrock College.
He lined out for the Ireland Under-18 Schools team in 2013 and also featured for the Netherlands at U-18 level, before moving to Canterbury in New Zealand at the age of 17.
Initially attending the Crusaders International High Performance Unit, he earned a place in the Crusaders Academy in 2014.
After impressing with New Brighton RFC, he was promoted to the Canterbury squad for the Mitre 10 Cup in 2016, and won NPC titles in 2016 and 2017.
Jager, who turns 31 next month, made his Super Rugby debut for the Crusaders in 2017. He was a key member of their squad for seven years, winning seven consecutive Super Rugby titles.
He played for the Provincial Barbarians against the British & Irish Lions in 2017, and was twice selected for the All Blacks XV under McMillan.
The front rower returned to Ireland when joining Munster from Crusaders in November 2023, and immediately established himself as an important squad member.
He made his Munster debut against Glasgow in December 2023 and quickly rose into international contention, making his Ireland debut against Wales during the 2024 Guinness Men's Six Nations.
He ended his debut campaign at Munster with 13 appearances, and earned selection for Ireland's summer tour to South Africa.
Jager's second season at the province saw him continue to impress. He made 14 appearances, including starts in the Investec Champions Cup knock-out clashes with La Rochelle and Bordeaux-Bègles.
Last season saw the well-travelled tighthead make eight appearances, and he played his final game for Munster against Ulster at Thomond Park in April.
Everyone at Munster Rugby wishes Oli and his family all the best for the future.
