Two cars were involved in the collision that occurred in the townland of Ballymascanlon.
The passenger of one of the cars, a male in his late teens, was fatally injured. His body remains at the scene at this time.
The driver of this car fled the scene on foot but has since presented himself to gardaí in Dundalk and is assisting them in the investigation.
The driver of the second car, a man, aged in his 40s, was taken to Our Lady of Lourdes Hospital, Drogheda with minor injuries.
The Garda Forensic Collision Investigators are due to commence their investigations shortly. The road remains closed at this time, and local diversions are in place.
Gardaí are appealing for anyone with information in relation to the incident to come forward, and for any road users who may have camera footage such as dash-cam and who were travelling in the Ballymascanlon area between 8pm to 9pm to make this footage available.
Anyone with information is asked to contact Dundalk Garda Station on 042 9388400, the Garda Confidential Line on 1800 666 111, or any Garda Station.
