This study aimed to identify the relationship between high levels of physical activity and the obesity rate among adolescents aged 11 to 14 years. The study adopted the descriptive analytical approach because of its suitability for the nature of the topic. The study population consisted of school-attending adolescents, from whom a representative sample of 120 male and female adolescents was selected. Data were collected using a physical activity questionnaire, in addition to anthropometric measurements used to calculate Body Mass Index (BMI) according to the standards of the World Health Organization (WHO). The results revealed a statistically significant negative relationship between high levels of physical activity and the obesity rate, as BMI was found to decrease as the level of physical activity increased among adolescents. The findings also showed statistically significant differences in obesity rates between adolescents with high and low levels of physical activity, in favor of those with higher activity levels. In addition, the study found statistically significant differences in the obesity rate according to the variables of gender and age group within the scope of the study. These findings confirm the important preventive role of physical activity in reducing obesity during adolescence. They also highlight the need to strengthen targeted physical activity programs within educational institutions, while taking into account age and gender characteristics, in order to establish healthy lifestyles that contribute to preventing obesity and improving the general health of adolescents.