The 40-year-old actor was a passenger in a Porsche that lost control and crashed in Santa Clarita, north of Los Angeles, killing both occupants.
A post by the actor's team on Facebook says the actor had been attending a charity event to raise money for people affected by Typhoon Haiyan, which hit The Philippines last month.
"We appreciate your patience as we too are stunned and saddened beyond belief by this news," the post said.
"Thank you for keeping his family and friends in your prayers during this very difficult time."
Celebrity news website TMZ, which first reported news of the death, says the car hit a post or tree and was quickly engulfed in flames.
The identity of the driver of the car is not known.
Film studio New Regency, which distributes through Twentieth Century Fox, tweeted its condolences to the actor.
It is with great sadness to report that @realpaulwalker has passed away. We will miss you. #RIP
— New Regency (@NewRegency) December 1, 2013
Walker's career began on the small screen, with roles in shows including The Young and the Restless and Touched by an Angel.
He rose to fame after starring in the 1999 hit film Varsity Blues, but is best known for starring as Brian O'Conner in a string of Fast and Furious movies.
His other film credits include Pleasantville, Into the Blue, She's All That and Takers.
He is survived by his teenage daughter Meadow.
Hoping it's not true though
