A National Monument (Irish: Séadchomhartha Náisiúnta) in the Republic of Ireland is a structure or site, the preservation of which has been deemed to be of national importance and therefore worthy of state protection. If the land adjoining the monument is essential to protect it, this land may also be protected.

Such monuments in Northern Ireland are officially called scheduled monuments and come under the protection of the Department for Communities.

National monuments are managed under the auspices of the National Monuments Service, which is currently part of the Department of Culture, Heritage and the Gaeltacht.^[1] The official status of "National Monument" is conferred under the National Monuments Acts 1930 to 2004.^[2]

Monuments were given protection before Partition and before the independence of most of Ireland in the early 1920s by the Ancient Monuments Protection Act of 1882, an Act of the Parliament of the United Kingdom of Great Britain and Ireland (as it then was). Irish monuments were similarly protected by the new Irish Free State under the National Monuments Act of 1930.^[3] The list of National Monuments has since been expanded. By 2010 there were nearly 1000 monuments in state ownership or guardianship, although this represents only a small proportion of Ireland's recorded archaeological heritage.^{[4] [5]} Each National Monument is numbered (for example, the Rock of Cashel is National Monument number 128, Newgrange is number 147),^[6] but a numbered monument may represent a group of sites, as is the case at the Rock of Cashel.

The most recent amendment act, the National Monuments (Amendment) Act 2004, includes provisions for the partial or complete destruction of National Monuments by the Government of Ireland if such destruction is deemed to be in the "public interest".^[7] These provisions were included, according to press reports, to facilitate road schemes, and in particular the destruction of Carrickmines Castle, a National Monument, to build an intersection along the south-eastern section of the M50 motorway.

The following is an index to lists of National Monuments of the Republic of Ireland, divided by province.