The R&B artist, 55, was convicted last September in New York of racketeering and sex trafficking crimes.
He had faced years of allegations and the judge on Wednesday said he had an “indifference to human suffering”
Lawyers for the singer, whose real name is Robert Sylvester Kelly, say he will appeal.
US District Judge Ann Donnelly said the celebrity had used sex as a weapon, forcing his victims to do unspeakable things and saddling them with incurable diseases.
The court heard how Kelly – known for hit songs like I Believe I Can Fly and Ignition – used his influence to lure women and children into sexual abuse over two decades.
Jurors at his six-week trial in Brooklyn heard how he trafficked women between different US states, assisted by managers, security guards and other members of his entourage.
The court also heard how Kelly had illegally obtained paperwork to marry singer Aaliyah when she was 15 in 1994, seven years before the singer died in a plane crash.
The certificate, leaked at the time, listed Aaliyah’s age as 18. The marriage was annulled months later.
Federal prosecutors had recommended that Kelly be sentenced to more than 25 years in prison, given the seriousness of his crimes and “the need to protect the public from further crimes”.
But his lawyers called for a sentence of 10 years – the mandatory minimum for his conviction – or less.
They portrayed Kelly as growing up poor in a household rife with domestic violence and suffering sexual abuse from a young age.
They said he was “devastated” by the sentence and planned to appeal.
Kelly has been in custody since he was indicted by federal prosecutors in New York and Chicago in July 2019.
His three years behind bars have been eventful, including a beating from a fellow inmate in 2020 and a bout with Covid-19 earlier this year.
The singer faces further legal action in August, when he goes on trial again, this time in Chicago on child sex images and obstruction charges.
He is also due to face sex abuse charges in courts in Illinois and Minnesota.