The body of Scott Ashley Sterling, 32, was found shortly after 11:30 p.m. Tuesday, Los Angeles County coroner's Lt. Larry Dietz said.
The death cast a pall on what has been a joyous season for the Clippers, normally an NBA doormat but now among the league's best teams. The team is in first place in its division and had a franchise-record 17-game winning streak that was snapped Tuesday.
The 77-year-old Sterling, a billionaire real estate mogul who purchased the team in 1981, had no immediate comment, nor did the team.
The death at a beachfront apartment building on Pacific Coast Highway was discovered after a friend of Scott Sterling called police after not hearing from him for several days, according to a statement from the Los Angeles County Sheriff's Department. Deputies found the body and paramedics pronounced him dead at the scene.
"Sheriff's homicide and Los Angeles County coroner's personnel at this time believe that Sterling died of an apparent drug overdose," the statement said.
Dietz said the death appeared to be accidental, but an autopsy was planned to determine the exact cause of death.
In 1999, the then-19-year-old Sterling was arrested for shooting his friend with a shotgun. Beverly Hills police said Philip Scheid was shot in the legs during an argument at Donald Sterling's mansion.
Scheid said he was shot from behind while running away. Sterling said he fired in self-defence after Scheid approached him with a knife. The county district attorney's office declined to file criminal charges, citing credibility problems with the victim.