The man – who was in his 60s – was struck by a blue BMW with a partial registration 01-G on the Gort Road in Loughrea at about half past eight.
Gardaí say the car drove away from the scene in the direction of Gort.
The victim was taken to University College Hospital Galway where he was pronounced dead shortly before 2am.
The road remains closed this morning for a forensic examination – and Gardaí are appealing for any witnesses to come forward.
