The collision happened on Glebe Street in Ballinarobe around 4:20 on Thursday.
The victim was severely injured at the scene and was brought to Mayo University Hospital, where she later died from her injuries.
Gardaí have asked for any witnesses, or people who were driving in the area with dashcam footage to come forward. Garda advice is to contact Claremorris Garda Station on 094 9372080, the Garda Confidential Line on 1800 666 111, or any garda station.
