The high-powered super-car burst into flames after it crashed in Santa Clarita, north of Los Angeles, at 3:30pm, yesterday.
Walker, 40, who was in five of the six films about illegal street racing and heists, had been at an event for his charity Reach Out Worldwide before deciding to take the car out for a drive with his friend.
The fundraiser, to benefit victims of Typhoon Haiyan, was taking place in a race car shop near to the scene of the crash.
Guests rushed to put out the flames with fire extinguishers but the fireball had already engulfed the car.
The star's representatives and official Facebook page confirmed his death.
The LA County Sheriff's department said two people died but is yet to release names.
However Ame Van Iden, Walker's publicist, said in an email: 'Sadly, I must confirm that Paul did pass away this afternoon in a car accident.'
The actor's official Facebook page was also updated with the message: 'It is with a truly heavy heart that we must confirm that Paul Walker passed away today in a tragic car accident while attending a charity event for his organisation Reach Out Worldwide.
'He was a passenger in a friend's car, in which both lost their lives.
'We appreciate your patience as we too are stunned and saddened beyond belief by this news.
'Thank you for keeping his family and friends in your prayers during this very difficult time. We will do our best to keep you apprised on where to send condolences. - #TeamPW.'
Walker, who leaves behind a 15-year-old daughter, was an investor in the Always Evolving car shop in Valencia, California.
