This article examines the social construction of upper-class white femininity at private Ontario girls’ camps in the 1920s and 1930s with specific focus on physical activity. Historically, prevailing social conceptions of what it means to be female has defined acceptable physical activity participation by girls. The daily life and activities at girls’ camps elucidates details of how girls’ camp both challenged and embraced early twentieth-century femininity. In these mostly female environments, although girls had the freedom to experiment with behaviors and activities outside the norm in the city, female camp directors held fast to some traditional ideals of femininity. Thus, the establishment of girls’ camps was both progressive and, at the same time, accommodated agreed-upon ideas about femininity. Using four of the oldest girls’ private camps in Ontario, this paper examines the intricacies of femininity during the early twentieth century.