Around the country: Monaghan stole a march on the rest of the country yesterday when it held its St Patrick's Day parade 24 hours early.
More than 3,000 people watched the hastily arranged spectacular, which included six marching bands as well as a host of floats and vintage vehicles and took over an hour to pass through the town centre.
Most cities and towns are sticking with convention today, however, by marching on the saint's feast itself.
Outside Dublin, the largest parade is likely to be in Cork, where the action gets under way at 1.30 p.m. on Grand Parade.
Ireland's Special Olympians will be the grand marshals and, in keeping with tradition, the band of the First Southern Brigade will lead the other participating bands and floats up Patrick Street and McCurtain Street.
As usual, the Cork event will be preceded by "The Fast and Furious Dash," a 60-metre sprint for men and women on McCurtain Street at 1.20 p.m.
In the North, a huge crowd is expected outside Belfast City Hall for an open-air concert featuring well-known pop music acts.
The headliners at the event are Six, Sinéad Quinn and Malachi Cush, who made their names on BBC's Fame Academy series.
They will be joined by other musicians, and there will also be street entertainment around the concert including face-painters and stilt walkers.
In addition, Belfast City Council is funding a concert in the Ulster Hall tonight that will feature both traditional Irish and Ulster-Scots entertainment. The main act is Capercaillie.
In the west, Galway's parade starts at 12.30 p.m. and will be preceded by a children's art workshop on the theme of the national day, in Árus na nGael, Dominick Street, while the parade in Castlebar, Co Mayo, starts at 3 p.m. at the industrial estate, next to McHale Park.
Limerick's parade, which starts at 11.30 a.m. from O'Connell Avenue, will be professionally choreographed for the first time.
It has been designed on the theme "Limerick, Past, Present and Future".
Elsewhere in Munster, the largest float ever seen in Waterford - a 140ft sea monster - will be part of that city's parade, which starts at noon from the junction of Bath Street and College Street.
Also in Waterford, there will be a parade in Dungarvan at 3 p.m.
Derry marks the saint's day with an afternoon of music at Guildhall Square, including You're a Star's Mickey Harte and the Emerald Ceilí Band, and culminating with the Fureys.
The North also sees St Patrick's Day events in cities and towns such as Armagh, Coleraine, Downpatrick and Cookstown.
