The two-car collision took place on the N51 at Boyerstown at around 7.45am on Thursday.
The woman who was killed was aged in her 40s and was a passenger in the car.
She was pronounced dead at the scene and her body was removed to Navan mortuary where a post-mortem examination is due to take place.
A teenage girl, who was a passenger in the same car, was seriously injured and was airlifted to Children’s Hospital Ireland, Temple Street.
The driver and a third passenger were also seriously injured and were brought by ambulance to Our Lady of Lourdes Hospital, Drogheda.
Gardai said they are both female but could not confirm their ages.
The driver of the second car was brought to Connolly Hospital Blanchardstown with non-life-threatening injuries.
The N51 at Boyerstown has been closed for technical examination by Garda forensic collision investigators.
Gardai are appealing to anyone who may have witnessed the collision, or who may have footage around the area or time of the incident, to come forward.
Meanwhile in a separate incident, a man in his 40s has died following a collision involving a truck and a van in Co Meath in the early hours of Thursday morning.
The incident took place on the M3 road at Dunshaughlin at around 2am on Thursday.
The driver of the van, a man in his 40s, was pronounced dead at the scene.
His body has been removed to Navan mortuary, a postmortem is due to be carried out, and the coroner has been notified.
The driver of the truck was taken to Connolly Hospital Blanchardstown as a precaution.
Northbound lanes between Junctions 5 and 6 on the M3 have been closed for gardaà to carry out a technical examination.
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News in 90 seconds – March 12
Gardaà are appealing to anyone who may have witnessed the collision to come forward.
Road users who may have camera footage (including dash-cam) and were travelling on the M3 between Junction 5 and Junction 6 between 1.15am and 2.15am on Thursday, March 12 are asked to make this footage available to investigating gardaÃ.
Anyone with information is asked to contact Ashbourne garda station on 01 8010600, the garda confidential line on 1800 666 111, or any garda station.
Investigations are ongoing, a garda spokesperson said.