Maintaining a high level of physical activity provides significant health benefits for children, particularly in enhancing cardiorespiratory fitness and maintaining a healthy weight. This study aimed to investigate the impact of weight status on children's hemodynamic parameters and aerobic fitness levels. This cross-sectional study included 350 rural primary school children (146 boys and 204 girls) aged 11-13 years, randomly selected from two schools in the King Cetshwayo District, KwaDlangezwa area of KwaZulu-Natal. The anthropometric measurements recorded included height, weight, waist circumference, and hip circumference, with percentiles calculated using Cole's Lambda, Mu, and Sigma method. Additionally, skinfold measurements were obtained at four sites (biceps, triceps, subscapular, and suprailiac). Hemodynamic measurements included systolic blood pressure, diastolic blood pressure, and heart rate. Aerobic fitness was assessed using the 20 m shuttle run test, which evaluated speed, level, and age. The healthy group demonstrated significantly lower ratios in several measurements compared to those of the overweight group, i.e., the VO2max was 6% higher (<0.001), the waist-to-hip ratio was 6% lower (<0.001), the body fat percentage was 16% lower (<0.001), the waist circumference was 12% lower (<0.001), and the resting heart rate was 3% lower (p ≤ 0.055). Differences in systolic and diastolic blood pressure were also observed, with the systolic pressure 2% lower (p ≤ 0.116) and the diastolic pressure 3% lower (p ≤ 0.086) in the healthy group. The study revealed a significant association between body weight status, aerobic fitness, and blood pressure parameters. Conducted in rural primary schools in KwaDlangezwa, KwaZulu-Natal, the research highlights notable correlations among weight status, aerobic competence, and blood pressure (BP) in children aged 11 to 13 years. The findings indicate that children with a healthy body weight showed higher VO2max levels and a reduced risk of developing childhood obesity and hypertension, unlike their overweight or obese peers, who displayed lower aerobic fitness and higher blood pressure.