Nirra Fields had 15 points to top the Canadians, who will meet the United States in Monday night's final and are guaranteed to match their best-ever Pan Am result.
Canada has never won a Pan Am basketball tournament, on either the women or men's side. The women's best result was a silver in 1999 in Winnipeg.
Lizanne Murphy scored 12 points, while Kim Gaucher and Michelle Plouffe had 10 apiece for a Canadian team that completely outclassed Brazil with its depth and hard-nosed defence.
The Americans played Cuba in the early semifinal, holding on for a 65-64 victory.