This study examines the associations between moderate-to-vigorous physical activity (MVPA) and sedentary time with cardiometabolic risk factors in children and adolescents. Data from 14 studies involving 20,871 children aged 4-18 years were analyzed using meta-analysis. MVPA was significantly associated with better cardiometabolic outcomes, including lower waist circumference, systolic blood pressure, fasting insulin, and triglycerides, independent of sedentary time. Higher levels of MVPA were associated with better cardiometabolic risk factors across different levels of sedentary time, with larger differences observed in those with lower sedentary time. Time spent sedentary was not associated with any cardiometabolic outcome after adjusting for MVPA. The findings suggest that MVPA is more important than sedentary time in relation to cardiometabolic health in children and adolescents.This study examines the associations between moderate-to-vigorous physical activity (MVPA) and sedentary time with cardiometabolic risk factors in children and adolescents. Data from 14 studies involving 20,871 children aged 4-18 years were analyzed using meta-analysis. MVPA was significantly associated with better cardiometabolic outcomes, including lower waist circumference, systolic blood pressure, fasting insulin, and triglycerides, independent of sedentary time. Higher levels of MVPA were associated with better cardiometabolic risk factors across different levels of sedentary time, with larger differences observed in those with lower sedentary time. Time spent sedentary was not associated with any cardiometabolic outcome after adjusting for MVPA. The findings suggest that MVPA is more important than sedentary time in relation to cardiometabolic health in children and adolescents.