The incident happened on the N5 this morning.
Gardaí in Castlebar are investigating a fatal road traffic collision that occurred on the Westport Road outside Castlebar at 8.30a.m. Thursday 14th June 2018.
A two-car collision occurred when one vehicle was in collision with a second vehicle.
The female driver believed to be in her 60s, was removed to Mayo University Hospital and was pronounced dead a short time later.
The second driver, a man in his 30s, was also removed to Mayo University Hospital with minor injuries.
The road is currently closed and local diversions are in place.
Gardaí are appealing to anyone who may have witnessed the collision or has information to contact Castlebar Garda Station on 094 - 9038200, the Garda Confidential Line 1800 666 111 or any Garda Station.