She was found dead in Redondo Beach on Wednesday, said the Los Angeles County coroner's office .
The tall, muscle-bound, raven-haired wrestler billed herself as the Ninth Wonder of the World because her wrestling predecessor Andre the Giant had already called himself the eighth.
She was a member of the wrestling squad that dubbed itself D-Generation X, often competed against men and at one point was the WWE women's champion.
A statement posted on her official website reads: "Today we lost a true icon, a real life superhero. Joanie Laurer aka Chyna, the 9th Wonder of the World has passed away. She will live forever in the memories of her millions of fans and all of us that loved her."
Laurer was a native of Rochester, New York, and graduated from the University of Tampa in Florida before taking up wrestling.
She joins a long list of WWE wrestlers who have died relatively young, including Rick Rude, Curt "Mr Perfect" Hennig, the Ultimate Warrior and Owen Hart.
After leaving WWE in 2001, Laurer posed for Playboy and appeared in adult films and on reality TV, including the shows The Surreal Life and Celebrity Rehab with Dr Drew.
Police said they found Chyna dead in her apartment after responding to a 911 call from a friend.
Redondo Beach police said the friend had gone to check on the wrestler after she had failed to answer her phone for a few days, and told the 911 operator that she was not breathing.