Background: Little is known about the epidemiology of clavicle fractures in United States (US) high school athletes. Sports participation among high school students has increased steadily, placing increased numbers at risk of sports-related injury. Purpose: To describe the epidemiology of clavicle fractures among high school athletes, including injury rates by sex, sport, and type of play and trends in operative versus nonoperative treatment. Study Design: Descriptive epidemiology study. Methods: The study data set included all athlete-exposure (AE) and clavicle fracture data collected from 2008-2009 through 2016-2017 from a large sample of US high schools as part of the National High School Sports-Related Injury Surveillance Study for students participating in boys’ football, boys’/girls’ soccer, boys’/girls’ basketball, boys’/girls’ volleyball, boys’ wrestling, boys’ baseball, girls’ softball, girls’ field hockey, boys’ ice hockey, boys’/girls’ lacrosse, boys’/girls’ swimming and diving, boys’/girls’ track and field, girls’ gymnastics, girls’ cheerleading, boys’/girls’ tennis, and boys’/girls’ cross-country. Results: Overall, 567 clavicle fractures were reported during 31,520,765 AEs, an injury rate of 1.80 per 100,000 AEs. Injury rates varied by sport, with the highest rates in the boys’ full-contact sports of ice hockey (5.27), lacrosse (5.26), football (4.98), and wrestling (2.21). Among girls’ sports, the highest rates were in soccer (0.92), lacrosse (0.26), and basketball (0.25). In sex-comparable sports, injury rates were still significantly higher among boys (1.03) than girls (0.35) (rate ratio, 2.91; 95% CI, 1.97-4.30). Injury rates were significantly higher in competition (4.58) as compared with practice (0.87) (rate ratio, 5.27; 95% CI, 4.44-6.26). Most injuries were treated conservatively (82.7%) rather than operatively (17.3%). Time to return to sports varied, with a greater proportion of medical disqualifications among those treated operatively (40.0%) as compared with those treated conservatively (22.6%) (injury proportion ratio, 1.77; 95% CI, 1.31-2.39). Conclusion: Although clavicle fracture rates are relatively low, they vary by sport, sex, and activity. Understanding such differences should drive more effective, targeted injury prevention efforts. Increased time loss from sports with surgical versus conservative treatment may have been influenced by factors including injury severity and its timing relative to the season’s progress.