Colm O'Gorman is resigning as Amnesty Ireland's executive director after 14 years in the role.
He is going to take up the role of Global Director for Community Engagement at the Global Refugee Sponsorship Initiative.
The vocal spokesperson on human rights issues said it had been a privilege to work with the organisation over the years.
He announced he was stepping down on Twitter this evening.
Colm tweeted: "Some news. After 14 years as Executive Director at Amnesty Ireland.
"I am moving on. It has been a huge privilege to work with so many incredible colleagues and partners over these years.
"I will always be tremendously proud of the work we have done together.
"In a few months I will take up the role of Global Director, Community Engagement at the Global Refugee Sponsorship Initiative. Community sponsorship for refugees is an area of work for which I have huge passion - and right now, the role of communities is more vital than ever.
"More on this to come, but I find myself with deeply conflicting feelings as I write this tweet - deep regret at the fact that I am leaving an amazing team and an incredible movement, and enormous excitement at prospect of the work that lies ahead.
"Heartfelt thank you to everyone at Amesty Ireland and all my Amnesty colleagues for the past 14 years - to our members, activists and partners.
"It has been the privilege of my life so far to work with you and for you. And to do the work we have done together."
Friends and colleagues thanked Colm for his hard work and dedication.
Amnesty Ireland wished him well in his new role.
They wrote: "Amnesty are announcing the departure of Executive Director Colm O'Gorman.
"During his 14 years at the helm, he has left an indelible impact on the advancement of human rights in Ireland & globally.
"We're sorry to see him go but wish him the very best with this new phase of his career."
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