An 18-year-old woman has died after a two-vehicle crash on the A487 in Aberystwyth at around 10pm on Saturday night.
Dyfed Powys Police said she was a passenger in one of the vehicles involved in the collision at Commins Coch.
The vehicle, a Vauxhall Astra, was travelling out of Aberystwyth towards Bow Street when it collided with a silver Audi A6.
Several others were also taken to hospital with serious injuries.
Officers are urging anyone travelling along this stretch of road at the time who had dash cam footage, or saw the collision or the vehicles involved, to come forward.