Based on a one-year longitudinal experimental study with 3,782 kindergarten school children across 15 countries, this article examines the association between prayer and happiness. Results show that the post-test scores on the faces scale were higher for the participant group who had taken the prayer lessons vis-à-vis the comparison group. Regression analyses showed that children from affluent countries, Christian children, those who took more prayer lessons, and those who regularly self-practiced were more likely to be happier. Hierarchical and Tobit regression models revealed that frequency of prayer lessons and self-practice were strongest predictors of post-test faces scale scores. The happiness promoting potential of prayer for kindergarten school children is foregrounded.