The collision occurred at approximately 4.30am on the A412 towards Iver at Denham.
The road is closed from junction one of the M40 towards Iver for investigation work at this time.
Sadly, the motorcyclist, a 34-year-old man, died at the scene of his injuries.
Investigating officer PC Colin Riley, of the Joint Operations Unit for Roads Policing, based at Amersham police station, said: “We are investigating this tragic incident that has resulted in the death of a 34-year-old man.
“I am asking anybody who witnessed the collision to please make contact with the police.
“I would also ask any drivers with dash-cams to please review their footage in case it has captured anything that can assist this investigation.
“You can call us on the 24-hour non-emergency number 101, quoting reference 43200401116 or make a report online.
“Alternatively, for 100% anonymity, you can call the independent charity Crimestoppers on 0800 555 111.
“The man’s next of kin have been informed and are being supported by officers at this time, although as yet, formal identification has not taken place.