Kamaal Maxamud Jaamac faces a single charge of assault.
Clashes broke out July 18 when Israeli supporters arrived at the rally in support of Palestinians killed by Israeli fire in Gaza.
Some men began pushing and shoving, and one man stomped on an Israeli flag before police moved in and separated the groups.
Calgary police had previously laid charges against two men and a teenage boy.
Charged with assault are Aziz Mohammed Madi, 18; Arlsan Khan, 27; and a 16-year-old youth, who cannot be named under provisions of the Youth Criminal Justice Act.