The crash happened at approximately 2pm yesterday on the N15 at Birchill and involved two vehicles.
The two men, aged in their 20s and 30s, were travelling in the same car and were pronounced dead at the scene. Their bodies have since been removed to Letterkenny University Hospital, where post-mortem examinations will be carried out.
Two passengers from the same vehicle, along with the occupants of the second car, were also taken to Letterkenny University Hospital for treatment. Their injuries are understood to be non-life-threatening.
A technical examination of the scene is currently underway, and local traffic diversions remain in place.
Gardaí are appealing to anyone who may have camera or dashcam footage from the area between 1:30pm and 2:30pm to come forward. Anyone with information is asked to contact Donegal Town Garda Station on 074 974 0190 or any Garda station.
