The comedian faces spending the rest of his life in prison after he was convicted of drugging and molesting a woman.
The 80-year-old TV star, known to millions as America's Dad, was found guilty of sexually assaulting Andrea Constand at his Philadelphia home in 2004.
The verdict came after a two-week retrial in which five other woman told the court they had also been drugged and violated by Cosby.
More than 60 woman in total have made similar allegations.
Cosby was convicted of three counts of aggravated indecent assault and could get up to 10 years in prison on each charge.
Shrieks erupted in the courtroom as the verdicts were delivered and some of his accusers whimpered and cried.
After the jury left the courtroom, Cosby stood up and shouted at a prosecutor who had argued he should be denied bail.
He called prosecutor Kevin Steele an "a**hole" and shouted: "I'm sick of him!"
The judge decided Cosby can remain on bail while he awaits sentencing.
Ms Constand, who waived her right to anonymity, told jurors that Cosby knocked her out with three blue pills he called "your friends" and then penetrated her with his fingers as she lay "frozen", unable to resist or say no.
During the trial, prosecutors said the entertainer was "nothing like the image that he played on TV" after his portrayal of father-of-five Cliff Huxtable on The Cosby Show from 1984 to 1992.
Cosby's lawyers claimed he was a victim of #MeToo, the movement against sexual misconduct, and likened it to a witch hunt or a lynching.
They accused Ms Constand of being a "con artist" who levelled false accusations against Cosby so she could sue him.
Lawyer Gloria Allred, who represented some of his accusers, said: "Justice has been done!"
Cosby, who has been married for 54 years, had previously confirmed sordid revelations about drugs and extramarital sex.
After Ms Constand brought a lawsuit against him a decade ago, Cosby acknowledged he had obtained quaaludes to give to women he wanted to have sex with. The sedative was a popular party drug before the US banned it more than 30 years ago.
Cosby also acknowledged giving pills to Ms Constand before their sexual encounter.
But he said they were the cold and allergy medicine Benadryl and insisted they were meant to help her relax.