Mr McKenna, 25, was walking home at 1.30am at Ballynally near Moville after attending a function at the Inishowen Vintage Show when he was struck by a car.
He was pronounced dead at the scene.
Another man who was understood to be walking home with Mr McKenna escaped unhurt.
The driver of the car, a woman in his 60s, was taken to hospital for assessment.
The scene was preserved to allow Garda Forensic Collision Investigators to examine the area and local traffic diversions were put in place but have now been lifted.
The local coroner, Dr Denis McCauley, was notified and the deceased was removed to the mortuary at Letterkenny Hospital, where a post-mortem examination will take place.
The young man’s family, including his mother and father, Michelle and James, are very well-known in the area.
Among those who expressed their sympathy to the family was the Donegal Ladies Gaelic Football Association of which Mr McKenna’s mother is the County Secretary.
Gardaí are appealing for witnesses following a fatal road traffic collision in Moville, County Donegal, on Sunday, 9th June 2024.
Gardaí are urging anyone who may have witnessed the collision to come forward.
Road users with camera footage (including dash-cam) from the Moville area around the time of the collision are requested to provide it to Gardaí.
Anyone with information is asked to contact Buncrana Garda Station at 074 932 0540, the Garda Confidential Line at 1800 666 111, or any Garda station.