The events were organised by the Right2Water group.
RTÃ‰ reports that demonstrations were held in various parts of the country including Dublin, Cork and Galway.
The Right2Water campaign is made up of community groups, political groupings and trade unions.
Brendan Ogle of the Unite trade union said the demonstrations were the first step in a significant pre-election campaign by Right2Water.
"Water has been a catalyst in the fight against austerity but people are crying out for a change in how our country is run and that will be visible on the streets of Dublin, Cork, Limerick, Galway and Donegal, among other counties today," he said.
The Irish Department of the Environment said three out of four people are now paying water bills.
This figure includes those on private schemes as well as those paying through Irish Water.
The department added that it did not think it prudent to advise people to get into debt by not paying their bills and urged them to engage with Irish Water.
Thousands of people in the Republic of Ireland have participated in 30 demonstrations about water charges.