The Deputy Governor of the Central Bank, Ed Sibley, is to leave the regulatory body this summer.
In a statement, the bank said Mr Sibley, who has responsibility for Prudential Regulation, will depart when his five-year term of office ends after August 31.
The bank said Mr Sibley would be pursuing "opportunities in the private sector."
In the meantime, it said Mr Sibley will step away from frontline regulatory and supervisory responsibilities, with interim arrangements to be announced in due course.
"Ed's departure will be a loss to the Central Bank and the European financial regulatory family," Central Bank Governor Gabriel Makhlouf said.
"He has made an enormous contribution in his current role as Deputy Governor and throughout his time at the Central Bank. Over the last decade he played an important role in building the resilience of Ireland and Europe’s financial system," Mr Makhlouf said.
"I would like to thank him for his leadership and commitment to the bank and in the area of financial regulation," he added.
Mr Sibley has been involved in the restructuring of the bank and the regulatory system in the wake of the financial crash.
He also played a lead role in driving the resolution of the long-term loan arrears problems in the financial system here.
He became one of two deputy governors at the Central Bank in 2017 after previously overseeing its supervisory work for all banks and credit unions.
Mr Sibley said it was with some sadness that he had taken the decision to leave the bank.
"It has been an immense privilege to work in the Central Bank over the last decade," he said.
"I am proud of all that the Bank has achieved and delivered for Ireland over this period, and the small part I have played in this," he said.
"The Bank has strong foundations to continue to deliver for the people of Ireland," he added.