Quinn Roux will leave Connacht when his contract expires at the end of the current campaign.
The second row joined Connacht from Leinster in the summer of 2014 and racked up 106 appearances over seven years.
His performances also saw him earn 16 Ireland caps while representing the province.
"This has been a really tough few months as I made a decision on my future," a statement from Roux read.
"There were a lot of factors at play, but most importantly I had to make a decision that was best for me and my wife Rentus and my daughter Rhemy.
"Rhemy is still very young and we feel the timing is right to go and experience something new as a family.
"I've been lucky to work with excellent coaches at Connacht and Ireland, and my thanks to them for all their guidance down the years, as well as the Connacht S&C, medical team and wider staff for their help.
"A special thank you to all the team-mates I’ve played with at provincial and international level. I’ve made some life-long friends and it’s been nothing but a pleasure sharing a pitch and locker room with them. Having the opportunity to represent my adopted country is something I’ll always be grateful for."
Head coach Andy Friend said: "It's no secret we would have liked to see Quinn stay at the club beyond this season.
"We entered into discussions but unfortunately as matters progressed, we were unable to reach a final agreement with him that worked on both sides.
"As a result, Quinn has decided at this stage of his career to explore other opportunities and we fully respect his decision in that regard."
