CONTEXT: Although sport-related internal organ injuries among athletes are relatively infrequent, combining data sources enables a more comprehensive examination of their incidence. OBJECTIVE: To describe the incidence and characteristics of sport-related internal organ injuries due to direct-contact mechanisms among high school (HS) and collegiate athletes from 2005-2006 through 2014-2015. DESIGN: Descriptive epidemiology study. SETTING: United States HS and collegiate sports data from 3 national sports injury-surveillance systems: High School Reporting Information Online (HS RIO), the National Collegiate Athletic Association Injury Surveillance Program (ISP), and the National Center for Catastrophic Sport Injury Research. PATIENTS OR OTHER PARTICIPANTS: High school and collegiate athletes in organized sports. MAIN OUTCOME MEASURE(S): Characteristics of the athlete, event, and injury were examined and stratified by data source and sport. Descriptive statistics of internal organ injuries via direct-contact mechanisms consisted of frequencies and incidence rates (IRs) per 1 000 000 athlete-exposures and 95% confidence intervals (CIs). RESULTS: During the 10-year period, 174 internal organ injuries were captured: 124 in HS RIO and 41 in the ISP; 9 were catastrophic. Most noncatastrophic injuries occurred among males (RIO = 85%, ISP = 89%), in football (RIO = 65%, ISP = 58%), and during competitions (RIO = 67%, ISP = 49%) and were due to player-player contact (RIO = 78%, ISP = 68%). The highest injury rates were in male contact sports: RIO football (IR = 11.7; 95% CI = 9.1, 14.2) and lacrosse (IR = 10.0; 95% CI = 3.1, 16.9); ISP: football (IR = 8.3; 95% CI = 5.0, 11.6) and ice hockey (IR = 7.9; 95% CI = 1.0, 14.7). A quarter of noncatastrophic injuries were season ending (RIO = 25%, ISP = 23%). Of the 9 catastrophic injuries, most occurred in HS (7/9) and football (7/9) and were due to player-player contact (6/9). Four resulted in death. CONCLUSIONS: Direct-contact internal organ injuries occur infrequently; yet when they do occur, they may result in severe outcomes. These findings suggest that early recognition and a better understanding of the activities associated with the event and use or nonuse of protective equipment are needed.