The two-day sentencing hearing at Montgomery County Courthouse in Pennsylvania starts on Monday.
At a retrial in April, the 81-year-old actor was found guilty of three counts of sexual assault against ex-basketball player Andrea Constand in 2004.
Ms Constand said she had viewed him as a "mentor" before he abused her. In June 2017, she described being given pills that left her "frozen" and unable to stop Cosby from assaulting her.
"I wasn't able to fight it in any way," she told the court. "I wanted it to stop."
On Monday, she tweeted a passage on containing anger from the New Testament.
There is a wide range of possibilities for Cosby's sentence.
He could receive a prison term of up to 10 years for each count - which legal commentators have said is unlikely to happen.
Alternatively, all three counts may be merged into a single term of up to 10 years.
There is no mandatory minimum for the convictions. That means Cosby could be sentenced to probation, or to continued house arrest. The 81-year-old has been free on $1 million bail, but has to wear a GPS monitoring device. He can only leave his home with prior permission, to meet his lawyers or get medical treatment.
One key issue for the sentencing hearing is whether Cosby will be designated a "sexually violent predator". If that happens, he will be obliged to register as a sex offender for life, instead of for a shorter timeframe decided by a judge.
Whatever the outcome, the sentencing marks an astonishing fall from grace for the comedian - the culmination of decades of sexual assault accusations from more than 60 women across the US.