The south-east has come up trumps in the latest litter survey by An Taisce.
Waterford has been judged the country's cleanest city, while Wexford is the cleanest town.
Sligo, Killarney and Letterkenny are ranked as the cleanest towns in Connacht, Munster and Ulster.
Limerick was the most littered city for the second year in a row, but the city has improved slightly since 2009.
Dr Tom Cavanagh, Chairman of Irish Business Against Litter, said towns would improve if businesses played a role in keeping pavements clean.