Physical inactivity, an unhealthy diet, smoking, and alcohol consumption are key determinants of morbidity and mortality. These health behaviours often begin at a young age and track into adulthood, emphasising a need for interventions in children and young people. Previous research has demonstrated the potential effectiveness of behavioural incentive (BI) interventions in adults. However, little is known about their effectiveness in children and adolescents. Eight bibliographic databases were searched. Eligibility criteria included controlled trials using behavioural incentives (rewards provided contingent on successful performance of the target behaviour) as an intervention component for health behaviour change in children and adolescents. Intervention effects (standardised mean differences or odds ratios) were calculated and pooled by health behaviour, using a random effects model. Twenty-two studies were included (of n = 8392 identified), 19 of which were eligible for meta-analysis: physical activity (n = 8); healthier eating (n = 3); and smoking (n = 8). There was strong evidence that behavioural incentives may encourage healthier eating behaviours, some evidence that behavioural incentives were effective for encouraging physical activity behaviour, and limited evidence to support the use of behavioural incentives for smoking cessation and prevention in adolescents. Findings suggest that behavioural incentives may encourage uptake and initiation of healthy eating and physical activity in young people. However, this is a limited evidence base and a wide range of incentive designs have yet to be explored. Future research should further investigate the acceptability of these intervention approaches for young people.