Jessica Chastain, a prominent supporter of the Me Too campaign, has said "consent must be given" after comedian Bill Cosby was convicted of drugging and sexually assaulting a woman.

A Pennsylvania jury found comedian Bill Cosby guilty on all counts of sexual assault at a retrial.

The 80-year-old was accused of drugging and sexually assaulting a then-friend, Andrea Constand, at his Philadelphia-area home in 2004.

Following the verdict, Jessica Chastain, who has been a vocal advocate of the Me Too and Time's Up movements, wrote on Twitter: "Just because you're rich and powerful doesn't mean another person's body is automatically available for sex. Consent must be given."

She added: "For anyone confused, here are some examples of when CONSENT IS NOT GIVEN," alongside a list of situations in which consent is absent.

Rose McGowan also spoke out about the verdict, writing: "Cosby is guilty. I'm sorry if you loved a lie.

"His victims can now exhale. Thank you judge and jury. Thank you society for waking up."

She added: "Profoundly happy that Cosby's victims, his survivors, are shedding tears of relief today."

Patricia Arquette added: "The state of America is this- Even with dozens of accusers we were all afraid Bill Cosby would walk."

Cosby could get up to 10 years in prison on each of the counts.