The former head of the children's hospital development board has been appointed to lead the new hospital group.
Dr Eilish Hardiman, a qualified nurse and chief executive at Tallaght Hospital, will be in charge of the Children's Hospital Group, bringing together the country's main paediatric centres on one site.
The new hospital is being built at St James', Dublin, at a cost of more than 484 million euro and is planned to open as late as spring 2018.
Planning permission for the new facility is not expected to be in place before the end of next year.
It will bring together the country's three existing paediatric hospitals - Our Lady's Children's Hospital, Crumlin; Children's University Hospital Temple Street and the paediatric service at Tallaght.
The board of the Children's Hospital Group will oversee the integration of the three hospitals in advance of the move to one site.
Dr Jim Browne has been appointed chairman and nine others will sit on the board.
James Reilly, health minister, said: "This appointment is another milestone for paediatric acute services in Ireland and I am delighted that a person of the calibre, ability and experience of Eilish Hardiman is taking up the role.
"The Government intends to make sure that our children get the best possible healthcare in the best possible environment. This announcement is another important step in achieving that for our children."
Tony O'Brien, director general of the Health Service Executive, said: "Eilish brings key relevant experience to this new challenge and she will have the full support of the HSE in ensuring the successful operational integration of the existing three children's hospitals in Dublin, in preparation for the opening of the new facility."