A man in his 50s has been arrested in connection with the collision - he's being held at Kildare Garda Station under Section 4 of the Criminal Justice Act.
It happened at around 8pm on Thomas Street in Newbridge last night where a woman in her 40s was found with serious injuries.
She was taken to Naas General Hospital where she was pronounced a short time later.
Gardaí say the results of a post-mortem will determine the course of the investigation.
Anyone with information to the incident or has dashcam footage are being asked to contact Newbridge Garda Station.
An Tóchar “Good Enough To Win” In Leinster, But Wary Of “Impressive” Wolfe Tones
Trio Of Wicklow Community Projects Officially Opened
Government's “Abysmal Housing Failures” Hitting Wicklow Families Says TD Brady
Gardaí Investigate Suspected Arson Attack On Cars Outside Arklow Family Home
Laughing Gas Is No Joke Warn Health Experts