A former pupil of the CBS in Limerick, the Patrickswell man has played a leading role in recapitalising the banking sector and restoring the economy.
Since his appointment as secretary general he has been involved in every significant decision taken by Finance Minister Michael Noonan throughout the bail-out programme, including those decisions which saw Ireland successfully exiting the programme.
Minister Noonan said that it was with great regret that he accepted a letter of resignation from Mr Moran and that he had valued his council during difficult times.
Mr Moran joined the Department of Finance in March 2011 and was second secretary in charge of banking. He was appointed secretary general in December 2012.
A lawyer by training, Mr Moran previously held senior roles with Swiss financial group Zurich Capital Markets and is a former head of wholesale bank supervision at the Central Bank.
He is also a member of the advisory committee of the National Treasury Management Agency.