Thousands of people are expected to turn out for Patrick's Day events all over the country today.
Traffic restrictions are in place on most parade routes and people are advised to plan their route before travelling.
Anyone travelling to the parade in Dublin is asked to leave their car at home, or outside the M50 ring road.
Traffic restrictions will be in place across the capital, as hundreds of thousands of viewers come into the city.
Superintendent Tom Murphy with the Traffic Division in Dublin, said: "We’re asking people, if possible to use public transport.
"If you have to use your car, if you are outside the M50 cordon, we'd ask you to leave it outside that cordon, and if you must travel within the M50 we'd ask you to leave it on the southside and not to go any further than the canal, and on the northside, the north circular Road.
"To leave it outside the security there and take public transport to the parade."
The President Michael D Higgins will attend the Dublin Parade.