One witness, Bronwin Page, said the animal, identified as a male Rhesus macaque, looked scared as it scurried between the ever growing crowd of people.
"We quickly realized it was a monkey wearing a coat and a diaper," Page told CBC radio. "That was pretty bizarre."
The owners surrendered the monkey, named Darwin, to authorities, who will donate the animal to an area primate sanctuary.
"He appears to be in good health," Toronto Animal Services supervisor Mary Lou Leiher said.