The collision occurred on the N69 Coast Road at Askeaton, Co Limerick, at around 1.30pm
The motorcyclist was pronounced dead at the scene and his body was removed to University Hospital Limerick.
The driver of the van, a man in his 50s, was taken to University Hospital Limerick to be treated for non-life-threatening injuries.
The road is currently closed to allow for a technical examination and local diversions are in place.
Gardaí are appealing to anyone with information, in particular any road users who were travelling on the N69 Coast Road (the Kilcornan side of Askeaton) at the time and who may have camera footage (including dash cam), to contact Newcastle West Garda Station on 069 20650.
