He must also serve 10 years of supervised release and register as a sex offender.
DuBois called the crimes "heinous" and said a guideline-range sentence was needed to punish Bey and protect the public from "sexual exploitation of children."
DuBois then revoked Bey's bail and ordered him taken into custody. He said Bey had failed to show that he was not a flight risk.
Assistant U.S. Attorney Josh Davison argued that Bey was a "predator."
Davison said in court papers that Bey had taken advantage of one of his victims - when she was 15 and "living a bare-subsistence life" in Egypt - by offering her food and money in exchange for sex.
Two of the illicit relationships, during which Bey fathered two children who were born when the victims were just 15, occurred after what authorities said were Islamic marriages.
"He knows these were not true marriages," Davison said. "They were a means for him to have sexual relationships" with underage girls.
Before sentencing, Bey apologized to the victims but said that he was "a wholehearted and faithful Muslim" and that none of the illicit relationships had been carried out without the consent of the victims' parents.
He insisted that he was not a predator or a pedophile and that his children - 12 borne by eight women - knew him to be a "loving father."
About 40 to 50 friends, family and others came to court yesterday to support him.
Defense attorney Fortunato Perri Jr. said Bey was not a sex tourist or a predator but someone who was a "good father" who had made "errors in judgment" by "following his faith to his detriment."
But the 20-year-old Philadelphia woman with whom Bey has a 5-year-old son and 2-year-old daughter called him "very sneaky, manipulative and conniving," adding: "He's not a good father at all." (Bey is under a court order to provide $180 a month in child support to the woman.)