A majority of U.S. children age 6–17 years do not meet the recommended 60 min of moderate to vigorous physical activity per day. Girls are less likely to meet these daily physical activity guidelines than boys. Following a call for greater gender-relevant physical activity programming, Aggie Play, an after-school physical activity program, engaged female student athletes to serve as active role models who lead girls through high-energy activities twice a week over a school year. The purpose of this study was to explore how Aggie Play affected girls’ self-efficacy and expected enjoyment for physical activity, time spent in various physical activity intensities during free play, and fitness, relative to a control group. Results revealed that the girls participating in Aggie Play increased ratings of physical activity self-efficacy and enjoyment compared with girls at a control site. Aggie Play girls also demonstrated greater improvements on the muscle-endurance test than girls at a control site. Results are consistent with prior gender-relevant physical activity and physical education research. This study extends prior results by documenting the benefits of gender-relevant physical activity programming when led by active female role models.