Green and blue spaces (GABS) are vital components of sustainable and healthy communities. Evidence suggest that GABS positively affect population health and wellbeing. However, few studies examine GABS influence on childhood obesity. This systematic review investigates the impact of GABS on childhood obesity particularly on children’s physical activity and eating behavior. The search protocol identified 544 studies from PubMed, Medline, PsycINFO, CINAHL, and Web of Science. A two-tier screening process document using the PRISMA flow diagram identified 16 studies which underwent quality analysis using the National Heart, Lung, and Blood Institute (NHLBI) and Critical Appraisal Skills Programme (CASP) tools. Data were interpreted using thematic analysis and narrative synthesis. Selected studies show varying sociodemographic characteristics of sampled populations located in urban and rural settings. The influence of GABS on children’s physical activity and eating behaviour depends on the type, location, proximity, density, facilities, and activity types that interplay with gender, ethnicity, and parent-child relationship. The review demonstrates the significant effect of GABS on children’s physical activity and eating behaviour. GABS provide children with safe venues for socialisation and long, intensive, and enjoyable physical activity; and influence children’s perceptions on vegetable consumption supporting healthier eating behaviour. These spaces have the potential to eradicate childhood obesity if policy, social, economic, environmental, and organisational considerations are addressed.