A judge in Pennsylvania has jailed US comedian Bill Cosby for three to 10 years for sexual assault.
Cosby, 81, was also categorised as a sexually violent predator, meaning he must undergo counselling for life and be listed on the sex offender registry.
The actor declined to make a statement when offered the opportunity.
At a retrial in April, Cosby was found guilty of three counts of sexual assault for drugging and molesting Andrea Constand in 2004.
Cosby's request for bail pending appeal was denied. He was also fined $25,000 (£19,000) plus the prosecution costs.
After the sentencing, he was led away in handcuffs from the courtroom. He was then driven to Montgomery County Correctional Facility.
Cosby's attorney had asked for his sentence to be restricted to house arrest, saying he was too frail for prison.
The actor had been under house arrest since April.
The comedian became a household name in 1980s America when he starred in the Cosby Show TV sitcom, playing the father in a well-to-do African-American family living in Brooklyn, New York.
Such was his popularity that he was dubbed "America's Dad".
"This was a serious crime," Judge Steven O'Neill was quoted as saying by CNN after pronouncing the sentence in the Montgomery County Courthouse in Norristown.
"Mr Cosby, this has all circled back to you. The day has come, the time has come."
What was Ms Constand's testimony?
In June 2017, the former Temple University basketball administrator described how Cosby, whom she had viewed as a "mentor", had given her pills that left her "frozen" and unable to stop his assault.
In her impact statement, as carried by the National Post, she said: "To truly understand the impact that the sexual assault has had on my life, you have to understand the person that I was before it happened."
"I was at the top of my game, certain that the groundwork provided by my education and athletic training would stand me in good stead whatever challenges lay ahead..." she said.
"After the assault, I wasn't sure what had actually happened but the pain spoke volumes. The shame was overwhelming. Self-doubt and confusion kept me from turning to my family or friends as I normally did. I felt completely alone, unable to trust anyone, including myself."
She wrote that she had stopped eating, sleeping and socialising. Tormented by nightmares, she finally told her mother the truth about what had happened.
"Bill Cosby took my beautiful, healthy young spirit and crushed it," she said. "He robbed me of my health and vitality, my open nature, and my trust in myself and others."
"Instead of looking back, I am looking forward to looking forward," she added. "I want to get to the place where the person I was meant to be gets a second chance."
Montgomery County District Attorney Kevin Steele paid tribute to Ms Constand, saying: "We are all better off because she is in our lives. You've heard about how this assault changed her life... To put herself out like this, for years, in front of a worldwide audience is extremely difficult for anyone.
"She could've lived a quiet life but she knew it was important to see that justice was served."
Cosby alone in court
Nada Tawfik, BBC News, Pennsylvania
Bill Cosby showed little emotion and no remorse during his sentencing. At this defining moment in his life, there were no family members or former cast mates with him for moral support.
The court was filled, though, with several of his accusers who sat in the rows behind Andrea Constand.
Model Janice Dickenson clapped her hands in anticipation and joy, others quietly held hands. Their relief was evident when his sentence was finally read out. This was a moment they never thought possible. And they had front seats to witness it.
What will happen to her abuser?
The three counts on which Cosby was convicted were merged into one after an agreement between the defence and prosecutors, AFP News agency reports.
Cosby can apply for parole after three years - such a request would be reviewed by a special committee.
However, he could end up serving the maximum 10-year-sentence.
Psychologist Kristen Dudley testified that Cosby showed signs of a mental disorder and was likely to reoffend.
Ahead of the sentence, the judge designated him a sexually violent predator, despite the defence's argument that Cosby's age and blindness meant he was not a threat.
Tuesday's classification means he will need to register with state police and notify any community he lives in of his sex offender status, as well as undergo mandatory counselling for life.
Neighbours, childcare centres and schools will have to be notified of his whereabouts.
Cosby's wife, Camille, did not attend the sentencing.
Cosby's spokesman, Andrew Wyatt, dismissed the trial as "the most racist and sexist" in the history of the US, and said the convicted man was a victim of a "sex war".
District Attorney Steele summed up Cosby's fall from fame to ignominy: "For decades the defendant has been able to hide his true self and hide his crimes using his fame and fortune.
"He's hidden behind a character... but it was fiction... He used his acting skills, that endearing TV persona, to win over his victims and keep them silent...
"Someone who has a lot of money, someone who is famous, someone who can get a lot of attention all over the world just by showing up some place to eat shouldn't get a free pass for his crimes or be allowed to walk free."
Are there other accusers?
Some 60 other women have accused Cosby of sexual misconduct but charges have not been brought because of the statute of limitations.
However, Cosby does face defamation lawsuits for branding his accusers liars.
"I'm overwhelmed by the number of women who were willing to go through this process with us… telling their stories of being drugged, assaulted or raped by Bill Cosby," said District Attorney Steele.
Lili Bernard and former model Janice Dickinson - both Cosby accusers present at the hearing - tweeted on Tuesday: "May justice be served! #MeToo".
With my brave, badass #survivorsister #JaniceDickinson now at #MontgomeryCountyCourthouse. 2nd & last day #BillCosby sentencing hearing. #JudgeStevenOneill just announced he’s ready to hand down sentence to our rapist. May justice be served! #MeToo #TimesUp #ERANow pic.twitter.com/Rpcg1DNrOL— Lili Bernard (@LiliBernard) September 25, 2018
The comedian was arrested in 2015 and a deadlocked jury resulted in a mistrial in June 2017.
This year's retrial occurred amid the #MeToo movement that has seen people worldwide come forward to share stories of sexual harassment and assault.