Speaking at the San Sebastian International Film Festival in Spain, the British dame added that Spacey "is, and was, a most wonderful actor" and shouldn't be edited out of films.
"I can’t approve, in any way, of the fact that — whatever he has done — that you then start to cut him out of the films," she said, according to Variety.
Spacey was replaced by Christopher Plummer in the 2017 film All the Money in the World, after BuzzFeed News first reported Spacey had made a sexual advance toward actor Anthony Rapp in the 1980s when Spacey was 26 and Rapp was 14.
Those reshoots were done prior to the film's release in a bid to try to salvage the movie from Spacey's involvement, but Dench seemed to suggest she believed people were campaigning to have Spacey edited out from past films.
“Are we to do what happened when he was replaced with Christopher Plummer? Are we to do that throughout history?"
"Are we to go back throughout history and anyone who has misbehaved in any way, or who has broken the law, or who has committed some kind of offense, are they always going to be cut out? Are we going to extrude them from our history? I don’t know…”
According to Variety, Dench made the comments in response to a reporter's questions about her costar from The Shipping News (2002).
Earlier in the press conference, she had first brought up Spacey by recalling how he had been an "inestimable comfort" during filming after her husband had died.
"He cheered me up and kept me going," she said.
Dench finished her defense of Spacey by saying, “I don’t know about the conditions of it, but nevertheless he is, and was, a most wonderful actor."
"I can’t imagine what he is doing now,” she said, pausing to add, “And a good friend.”