Gere, an outspoken supporter of the Tibetan cause and a follower of the Dalai Lama, said there ‘absolutely’ should be a worldwide boycott of the Games if Beijing mishandled protests that official Chinese media say have left seven dead.
"In this situation if the Chinese do not act in the proper way, change their ways, acknowledge what is going on, allow free access to communication, then I think that absolutely we have to boycott the Games,” Gere told BBC radio.
"It would be unconscionable if we continued as if things are hunky dory and everyone's happy. It's impossible," he said.
The biggest protests against Chinese rule in Lhasa since 1989 which coincided with the 49th anniversary on March 10 of a failed uprising that led to the Dalai Lama's departure into exile led to clashes between demonstrators and police on Friday.
Witnesses told AFP tanks and other military vehicles had been deployed, along with police and soldiers, across the city.
Gere said he had not previously supported a boycott, believing the Olympics facilitated ‘the free exchange of communications, of sports, entertainment’.
He said of the protests: "You see this around the world with people who have been repressed, who are on the edge of extinction, and there's nothing left for them to do."