The incident happened in County Offaly
She had been walking along the Clara to Ballycumber road in the Erry area at around 7.30pm yesterday evening.
It's the fifth death on the country's roads in the past three days.
The road is closed for forensic examinations to take place.
Anyone with information, or who has dashcam footage in the area is being asked to contact Tullamore Garda Station.
