R Kelly has been found guilty of racketeering and sex trafficking after a trial in New York.
The racketeering charge includes 14 underlying acts – including kidnapping, forced labour and sex trafficking.
He was also found guilty of eight counts of violating the Mann Act, which is a federal law making it illegal to transport people across state lines for the purposes of prostitution or debauchery.
During the trial, the R&B singer - best known for the 1996 hit ‘I Believe I Can Fly’ - was accused of exploiting his fame to lure women and underage girls for sex.
He pleaded not guilty to all charges; however, a jury of seven men and five women found Kelly guilty on all counts of racketeering after just their second day of deliberations.
Kelly, whose face was shielded by a white mask, kept his head down as the verdict was read.
"Today's guilty verdict forever brands R Kelly as a predator, who used his fame and fortune to prey on the young, the vulnerable, and the voiceless for his own sexual gratification," acting US Attorney Jacquelyn Kasulis said.
"A predator who used his inner circle to ensnare underage teenage girls, and young women and men, for decades, in a sordid web of sex abuse, exploitation and degradation.
"To the victims in this case, your voices were heard and justice was finally served."
Peter Fitzhugh, a Homeland Security investigations agent, said the verdict brought an end to Kelly's "decade-long reign of terror over many vulnerable girls, boys and young women".
Prosecutors argued that his entourage of managers and staff who helped Kelly meet girls and keep them under control amounted to a criminal enterprise.
Despite the abuse, the singer continued to tour and make music - even after it came to light that he had married R&B star Aaliyah when she was just 15.
The court heard that he had ordered a former manager to fake documents in order for the marriage to be conducted.
Gloria Allred, a lawyer for some of the victims, said: "I have been practising law for 47 years. During this time, I have pursued many sexual predators who have committed crimes against women and children.
"Of all the predators that I have pursued however, Mr Kelly is the worst for many reasons."
"R Kelly thought that he could get away with all of this, but he didn't," Ms Allred said outside the courthouse.
"Despite the fact that he thought he could control all this, he was wrong."
Speaking outside the courtroom, Deveraux Cannick, a lawyer for Kelly, said the defence was "disappointed".
"I think I'm even more disappointed the government brought the case in the first place given all the inconsistencies," Mr Cannick said.
Kelly, whose full name is Robert Sylvester Kelly, faces up to 20 years in prison and is due to be sentenced on May 4th.
He is one of the most prominent people tried on sex abuse charges during the #MeToo movement following accusations that had been following him since the early 2000s.
Additional reporting: IRN