He is replacing David Franks, who left in March
The board of Irish Rail has selected Jim Meade to be the new chief executive.
He is replacing David Franks who left in March to be chief executive of Keolis Downer in Australia.
Mr Meade, a native of Co Clare, has been acting chief executive since that time.
He has previously been director of train operations since March 2013, responsible for the delivery of passenger and freight services.
He began his railway career as an apprentice fitter in 1979, joining the company in Limerick after finishing his apprenticeship in 1983.
He has also worked in a range of roles - including fleet maintenance management, strategic change programmes and district manager Limerick.
Frank Allen, chairman of Iarnród Éireann, said: "Jim's leadership of the Iarnród Éireann team will ensure that our rail network and services can play the strongest possible role in addressing economic and societal issues such as congestion and sustainability, achieve a financially sustainable future for the company and most importantly deliver a safe and customer focused service."
Speaking on his appointment, Mr Meade said: "I am honoured to have been selected as chief executive of Iarnród Éireann.
"I look forward to working for our customers to deliver a safe, and customer-focused rail service; with our team of over 3,800 colleagues to ensure we benefit from and value the contribution of every employee and provide opportunities for career progression."
He also said he wants to work with stakeholders "including the Minister for Transport, his department officials and the National Transport Authority to maximise the benefit to the country of investment in our infrastructure and services under the National Development Plan."