(1) Background: This study explores the potential energy expenditure associated with participation in after-school sports activities among primary school children. (2) Methods: The study involved 129 children age (11.35 ± 0.55 years) recruited from eight different public after-school sport programs. (3) Results: Data analyses revealed significant differences between the eight sports in total calories per session, calories per minute, and METs (p < 0.05). All sports showed higher energy expenditure compared to chess (p < 0.05), with soccer and rugby exhibiting the highest energy expenditure per session. Team sports showed elevated energy consumption per session (p < 0.01, r > 0.30), calories per minute (p = 0.01, r > 0.40), and METs (p < 0.01, r > 0.40) in comparison with individual sports. (4) Conclusions: These findings enhance our understanding of the energy expenditure observed in primary school children following various after-school sports activities. The results indicate that team sports, in particular, are pivotal in elevating physical activity levels, thereby playing an essential role in fostering healthier lifestyles among children.