The crash, which involved the bike and a Range Rover, took place at about 19:30 BST on Saturday at Groesonen Road in Clytha, near Abergavenny.
The driver of the Range Rover was arrested on suspicion of causing death by dangerous driving.
The motorcyclist, from Bristol, was pronounced dead at the scene.
A motorcyclist has died after a crash in Monmouthshire, Gwent Police has said.