The female athlete triad is often found in sports that value leanness and aesthetics and can lead to adverse health effects. We aimed to compare knowledge and risk of the triad among adolescent figure skaters, dancers, and runners. We advertised our survey on social media platforms: sports-specific forums; Facebook; and Instagram. We received 928 responses. We included female figure skaters, dancers, and runners aged 25 years or younger (N = 712). We asked participants to name the triad components and dichotomized knowledge scores as high or low. We developed a 6-question triad risk scale and defined “at risk” if participants endorsed 3 or more questions. Of 712 participants: 60% were figure skaters; 28% dancers; 12% runners; 78% were adolescents (≤17 years of age); 22% young adults (18-25 years); 12% had heard of the triad. A higher proportion of runners than figure skaters and dancers had high knowledge of the triad (16% vs 6% vs 5%, P < .01). Overall 60% of athletes were “at risk” of the triad, 25% skipped a period for 3 or more months, and 34% had a history of stress fractures or shin splints. Young adults vs adolescents and dancers vs figure skaters and runners had nearly twice the odds of triad risk. Most athletes were at risk of the triad but few knew about it. Dancers were at higher risk compared with figure skaters and runners. Efforts should be made to raise awareness of the triad among athletes, parents, and coaches, with special attention paid to the dance community.