The academy said its board of governors met on Tuesday night
The board of governors of the Academy of Motion Picture Arts and Sciences (AMPAS) has voted to expel actor Bill Cosby and film-maker Roman Polanski from its membership.
The academy said its board of governors met on Tuesday night and voted on their status in accordance with their Standards of Conduct.
The AMPAS, which runs the Oscars, also expelled producer Harvey Weinstein last year over mounting accusations against him.
He denies all allegations of wrongdoing.
Bill Cosby has been confined to his home until he is sentenced, after being found guilty of sexually assaulting a woman.
He was convicted of drugging and molesting Temple University employee Andrea Constand at his Philadelphia mansion in January 2004.
The 80-year-old TV star was convicted of three counts of indecent assault.
He could face up to 10 years in prison on each charge.
Polanski plead guilty in 1977 to the rape of a 13-year-old girl. He remains a fugitive after fleeing the US in 1978.
However a court in Poland ruled out extradition back in 2015.
Judge Dariusz Mazur explained that extradition would violate Polanski's human rights as he may be subject to confinement.
"I find no rational answer to the question: what is the real point of the US extradition request?" Mazur said at the time.
He argued that Polankski had served his time during a 42-day US prison stint in 1977 and 10 months of house arrest in Switzerland - where US prosecutors unsuccessfully sought extradition.
Polanski won an Oscar for Best Director in 2002 for 'The Pianist'.