Bill Cosby paid the woman accusing him of sexual assault almost $3.4m (£2.4m) in a civil settlement in 2006.
The figure was revealed during opening remarks at the actor and comedian’s retrial in Pennsylvania on Monday.
Mr Cosby, now 80, denies drugging and sexually assaulting former basketball player Andrea Constand 14 years ago.
The actor, who starred in the 1980s TV series The Cosby Show, has faced allegations from dozens of other women but has denied them all.
His first trial, in June 2017, ended when the jury failed to reach a verdict.
The existence of the civil settlement between Mr Cosby and Ms Constand in 2006 was known about at the time of the first trial. The amount, however, was previously kept confidential.
Last week, Judge Steven O’Neill ruled that it could be revealed to the jury in the course of the new trial.
The retrial takes place in the light of the #MeToo movement, which has raised awareness of alleged sexual misconduct by a number of powerful media figures.
Protesters, waving placards reading “justice for survivors”, gathered outside the courtroom ahead of the retrial.
One topless protester was charged with disorderly conduct. She was later identified as Nicolle Rochelle, who appeared on The Cosby Show four times between 1990 and 1992.
Mr Cosby has been charged with aggravated indecent assault, which could carry a prison sentence of up to 10 years.
His lawyers say he and Ms Constand shared a romantic relationship after they met at Mr Cosby’s old university.
Ms Constand, who is from Canada, had played basketball professionally in Italy and for Canada’s national women’s team.
When the alleged attack took place, Ms Constand was working as director of operations for the women’s basketball team at Temple University, Philadelphia.
Around 60 women over five decades have publicly accused the Emmy award-winning actor of being a sexual predator. But statute of limitation laws mean that only one charge has been brought to trial.
The retrial will be before the same judge and district attorney as the first trial – but the judge will this time allow five additional accusers to give evidence.
From trailblazer to alleged assaulter
He rose to fame as the first black actor to star in a major drama series, I Spy, in 1965.
The role earned him three of his four Emmy awards before he created several shows including the influential The Cosby Show in 1984.
In January, the comedian performed his first stand-up gig since 2015, for which he was criticised by some on social media.