An Post says 159 postmasters will retire and their business will be transferred to neighbouring post offices.
The company has today published the locations of the post offices that will close under its consolidation plans.
An Post says all remaining 960 post offices will benefit from investment and enhanced services and products.
11 post offices will close in Mayo, 18 in Co Galway, % in Roscommon and 6 in Co Sligo.
The Mayo post offices listed are Ballindine, Ballyglass, Belcarra, Carrowmore-Lacken, Cross, Doocastle, Finney, Hollymount, Kilmaine, Partry and Scardaun.
In Roscommon, the post offices in Athleague, Cornafulla, Granlahan, Loughglynn and Knockvicar will close.
In Sligo, those earmarked for closure are Ballinafad, Ballinfull, Dromard, Drumcliffe, Gurteen and Monasteraden.
And Co Galway is to lose 18 post offices - Ballyconnelly, Ballyglunin, Ballymoe, Cloghbrack, Colemanstown, Cornamona, Eyrecourt, Garrafrauns, Glinsk, Inverin, Kiltulla, Kylebrack, Lettermullen, Menlough, Moyard, New Inn, Renvyle and Woodlawn.
An Post says Post Offices in locations where postmasters are opting to retire will close, and the services will be consolidated with neighbouring post offices, ensuring their continued viability.
16 post offices have already closed at the request of the retiring contractor.
The company says all of the Post Offices that are closing are in locations with populations of less than 500 people, and all are within 15km of at least one other Post Office.