Phylicia Rashad, who starred in The Cosby Show, tweeted on Wednesday that "a terrible wrong has been righted".
The tweet was then removed. A follow-up post said she "fully supported sexual abuse survivors coming forward".
Cosby has defended Rashad after Howard University, where she is a dean, said her first tweet "lacked sensitivity".
The university, based in Washington DC, issued a statement that read: "Survivors of sexual assault will always be our first priority.