Police are appealing for witnesses.
A black Mercedes and a motorcyclist collided on the B4437, near Shipton-under-Wychwood at the crossroads with Leafield Road, yesterday at around 1pm.
Sadly, a 50-year-old man from Oxfordshire was pronounced dead at the scene. His next of kin have been told.
The driver of the Mercedes wasn't injured in the crash.
PC Sandra Terry of the Serious Injury Collision Unit, based at Bicester, said: "Our thoughts remain with the family of the man who died following this collision.
"We are carrying out a thorough investigation and we are appealing for the public's help.
"We are asking any motorists who were travelling on the B4437, near Charlbury and may have seen either vehicle prior to the collision to please come forward.
"Additionally if you have dash cam footage that captures either vehicle prior to or during the collision then we would ask you to also get in touch."
Anyone with information can report online or call 101 quoting reference 43200239098.