The women were each allegedly assaulted between 1979 and 1992 in Las Vegas, Lake Tahoe, and Reno homes, hotels and dressing rooms.
Lise-Lotte Lublin, one of the women named in the Nevada lawsuit, had previously accused Cosby of drugging her in a Las Vegas hotel room in 1989.
Lublin said Cosby gave her two drinks that made her dizzy, and that he asked her to sit between his legs and stroked her hair before she blacked out.
Other accusers in the lawsuit include Janice Dickinson, Janice Baker Kinney, Lili Bernard, Heidi Thomas, Linda Kirkpatrick, Rebecca Cooper, Pam Joy Abeyta and Angela Leslie.
Cosby's spokesperson, Andrew Wyatt, told US media that the women suing Cosby were motivated by their "addiction to massive amounts of media attention and greed."
They were able to sue after Nevada scrapped the civil statute of limitations for sexual abuse cases involving adults on May 31. The state had previously imposed a two-year limit for those over 18 to bring forward their cases to court.
Cosby, 85, was a towering figure in late-20th century American popular culture, and was once known as "America's Dad" for his part on "The Cosby Show," which ran from 1984-92.
He has been accused of predatory behavior by dozens of women in allegations that stretch back decades.
Around 60 women have accused Cosby of being a calculating, serial predator who plied victims with sedatives and alcohol before assaulting them over four decades.
Despite numerous lawsuits brought against him, Cosby has no criminal convictions, but was found liable last year in a civil case.
He was imprisoned in a criminal case in 2018, before being freed in 2021 when his conviction was overturned on a technicality.