The policeman, who starred on Sky One series Road Wars, was on duty at the time of the accident, in which a 91 year old also died.
Thames Valley Police confirmed the tragic news on their Facebook page.
The post, shared with their 105k followers, read: “Officers remain at the scene of a collision on the A4, Bath Road, Wargrave which occurred this afternoon at about 1.50pm.
“The collision involved a car and motorcycle which was being ridden by on-duty police officer PC James Dixon.
“Sadly a passenger in the car and PC Dixon died following the incident. The passenger in the vehicle was a 91-year-old woman.
“PC Dixon was based at Loddon Valley police station. Next of kin have been informed.”
Antonio Carluccio has died, aged 80, on November 8 [Getty]
They also revealed the IPCC have been notified of James’ death, and will be investigating the crash.
IPCC Associate Commissioner Guido Liguori later told the Mirror: “We have been notified by Thames Valley Police of a collision on the A4 near Reading, in which, tragically, a 91-year-old woman and a police officer have died.
“My thoughts and sympathies are with their families and friends and the colleagues of the officer at this very difficult time.
“IPCC investigators are attending the scene as part of an independent investigation to determine the circumstances which lead to the collision.”
Following the news, fans rushed to Twitter to share tributes to the late star.
“Growing up I was a big fan of PC James ‘Dixie’ Dixon and his @tvprp colleagues as they featured in #RoadWars,” one wrote. “Its well respected officers like PC Dixon that inspire me to be a Police Officer.
“My thoughts are with all those who knew him at this very difficult time #PCJamesDixon.”
“Dixie. Thoughts with his family and colleagues . He was a decent cop on #RoadWars,” another posted.
While a third added: “R.I.P ‘Dixie’ PC James Dixon from #roadwars.”
And a fourth added: “Such sad news about PC Dixson. Thoughts go out to his family friends and all at TVP. Was he part of the proactive team that featured on Road Wars.”