Russell Brand has been accused of sexually assaulting an extra on the set of 2011 film Arthur.
A lawsuit was filed in New York, and is the first accusation to be made against him in court.
British police are still investigating claims against Brand after multiple women made accusations, including rape, against the comedian in September.
Brand has previously denied all the claims against him, saying all sexual relations were consensual.
He and his representatives have yet to respond to this lawsuit.
The US case was brought under the Adult Survivors Act, which gives a one-year window to sue over alleged sexual abuse from a long time ago.
Warner Brothers, which distributed Arthur, is also named as a defendant – as are other firms involved in making the movie.
The lawsuit accuses them of tolerating Brand’s misconduct on set and aiding and abetting the alleged offence. They have yet to comment.
The accuser says she was hired as an extra for a scene filmed at Le Cirque restaurant in Manhattan in July 2010.
Brand was intoxicated during filming, according to the lawsuit, and is accused of exposed his genitalia in front of everyone while sat at a table staring at the woman.
It’s alleged Brand later followed her into a bathroom where he pulled down his pants and shoved her into a cubicle, forcing her to perform oral sex.
A crew member is said to have stood directly outside, as if guarding the door.
The woman – who is seeking unspecified financial damages – says she suffered “severe psychological injuries” and economic losses after the alleged attack.
The first claims against Brand were made in an investigation by The Sunday Times, The Times and Channel 4’s Dispatches.
They are alleged to have happened when he was at the height of his fame, but no charges have been brought.