Sean Young won't face any charges after allegedly slapping a security guard at an Oscars after party last week -- this according to the L.A. City Attorney.
You'll recall ... the "Ace Ventura: Pet Detective" star was arrested at the Governors Ball when she got into a dispute with a security guard, who accused her of not having a ticket. We're told the guard put his hand on Sean, and she slapped him.
Sean was arrested and booked on misdemeanor battery -- but a rep for the L.A. City Attorney's office tells TMZ, "Our prosecutors declined to file charges ... due to insufficient evidence."
The rep adds, "No further action is expected."
And this will probably be the last story that ever features both Sean Young and the Oscars.