Background: Practice of yoga has been linked to emotional awareness and positive moods as characteristics of happiness. There is a need to investigate whether a customized yoga programme enhances emotional awareness and happiness in children. Objective: This article reports a two-year multi-city study examining the effects of a customized Chinmaya Mission anchored Bala Vihar yoga programme on the emotional awareness and happiness of children. Method: For this repeated measures waitlist control design study, participants comprised 1589 children across 20 global cities and an equal number in the comparison group. Bala Vihar yoga programme participants had greater emotional awareness and scored higher on the happiness measure at phase 2, vis-à-vis the comparison group. Results: Participant children from American cities, girls, middle class children, those whose mothers were their primary caregivers, who lived in standard family arrangements, single children, who scored lower on the clinician-rated pediatric anxiety screening measure at phase 2, who attended most of the Bala Vihar yoga lessons and regularly self-practiced, were more emotionally aware and happier than their counterparts. Self-practice regularity was the strongest predictor of phase 2 scores. Conclusions: Results emphasize the positive emotions promoting potential of yoga for children, cross-culturally, with some modifications for certain subgroups of children. Though this study was primarily with Hindu children, some components such as postures and meditation could also be replicated with a wider cross-section of children.