Study Objective This study aimed to examine the relationship between body composition and fitness performance among Malaysian military cadets. Methods A cross-sectional study was carried out on 270 Malaysian military cadets, with 244 (90%) completing the physical tests. Measurements included height, weight, body mass index (BMI), body fat percentage, muscle mass, muscle percentage, basal metabolic rate (BMR), water weight, water percentage, sit-up count, push-up count, and predicted VO2max (2.4 km run test). Descriptive statistics and correlation analysis were conducted to examine the relationship between body composition and fitness performance. Results The results show that body composition has a weak negative correlation with push-up performance, with statistically significant p-values (< 0.01). This indicates that increases in factors like body weight, BMI, fat percentage, muscle mass, basal metabolic rate, and water mass slightly decrease upper body muscular endurance. However, push-up performance has a weak positive correlation with muscle and water percentages, also with significant p-values (< 0.01). VO2max, a measure of cardiovascular endurance, has a moderate negative correlation with body weight and BMI, with significant p-values (< 0.01), suggesting that higher values in these areas moderately reduce cardiovascular endurance. The correlation between body composition and sit-up performance is very weak, indicating a minimal relationship, but this correlation is not statistically significant. Conclusion The study emphasizes the significance of optimal body composition for improved physical performance. Military cadets should have a lower BMI and body fat percentage, as well as more muscle mass and muscle percentage, to perform optimally.