[Read reactions to the verdict.]

“Enough of that,” Judge Steven T. O’Neill said. He did not view Mr. Cosby as a flight risk, he said, adding that he could be released on bail but that he would have to remain in his nearby home. The judge did not set a date to sentence Mr. Cosby on the three counts, all felonies and each punishable by up to 10 years in state prison.

The National Organization for Women called the verdict a “notice to sexual predators everywhere.” Rose McGowan, one of the women who has accused Harvey Weinstein of assault, tweeted a thank you to the judge and jury and to “society for waking up.” Gloria Allred, the lawyer who represented many of Mr. Cosby’s accusers, hailed the decision as an important breakthrough.

“After all is said and done, women were finally believed,” she said outside the courtroom.

The impression of change was evident within the trial itself when the defense attacked the credibility of five women who had testified that they, too, believed Mr. Cosby had drugged and sexually assaulted them. Kathleen Bliss, one of Mr. Cosby’s lawyers, called one of the women a failed starlet who slept around. She branded another a publicity seeker.

The remarks inflamed Kristen Gibbons Feden, a prosecutor on the case. She called the attacks filthy and shameful and the sort of criticism that had long kept sexual assault victims from coming forward. Ms. Feden’s colleague, M. Stewart Ryan, described Ms. Bliss’s approach as “the last vestiges of a tactic not to get to the truth, but to damage character and reputation.”

Their boss, Kevin R. Steele, the Montgomery County district attorney, referenced the broader significance of the case when he thanked Ms. Constand for taking part in not one, but two trials. “She has been a major factor in a movement that has gone in the right direction, finally,” he said.