More than 40,000 runners and walkers are to take part in the biggest all-women event of its kind in the world.
The Flora Women's Mini Marathon will be held in Dublin city, with some of Ireland's leading personalities and broadcasters taking part.
Participants raised almost 14m euro for hundreds of charities last year - when the race was won by Dublin runner Linda Byrne in 34 minutes 29 seconds.
Since it started in 1983 some 780,000 women have collected close to 137m euro.
The 10km race starts of Fitzwilliam Square at 3pm.
Motorists are warned that roads will also be closed around St Stephen's Green, Merrion Square, Nutley Lane, Stillorgan Road, Donnybrook village, Morehampton Road and Leeson Street. Diversions will be in place.
Organisers said women of every age, size and walk of life from every county in Ireland will be taking part.
The event also attracts entrants from all over Europe, Australia, New Zealand, United States, Canada, Saudi Arabia, Iran and Japan.