In Co Mayo, a man in his late 50s died in a single-vehicle crash near Louisburgh.
In Waterford a man believed to be in his late 30s was killed when a truck collided with a car on the N25.
Both crashes are being investigated by gardaí.
Elsewhere, a man in his 70s has died in a collision at Ardfert in Co Kerry.
The man was leaving a shop in the village just after three o'clock this afternoon when he was involved in a collision with a truck.
He died at the scene.
The scene was sealed off and a technical examination is being conducted by Garda forensic road crash investigators.
Gardaí are treating the man's death as a tragic accident.
