The motorcyclist, aged in his 30s, was pronounced dead at the scene.
The road remains closed for a forensic examination.
Gardaí are appealing for witnesses, particularly road users with camera footage, to contact Listowel Garda station on 068-50820, the Garda confidential line on 1800-666111, or any Garda station.
Earlier, Gardaí also appealed for information regarding a hit-and-run in Co Galway which took place in the early hours of Sunday morning.
Officers and emergency services attended the scene in Loughrea shortly after 2am, where a collision had taken place involving a motorcycle and another vehicle which failed to remain at the scene.
The motorcyclist, a man in his 50s, and the pillion passenger, a woman in her 30s, were both taken to University Hospital Galway to be treated for serious injuries.
Gardaí are appealing to anyone who may have witnessed this collision or anyone with information to come forward.
Anyone with information is asked to contact Loughrea Garda station on 091-842870, the Garda confidential line on 1800-666111, or any Garda station.