This article tests how religion relates to helping strangers, an important but rarely studied measure of social solidarity and informal social capital. It uses the Gallup World Poll, a survey with nationally representative samples of 179,961 respondents from 126 countries. It finds that religious people, members of minority religions, and people in religiously diverse countries were more likely to help a stranger. Individuals living in devout countries were more likely to help strangers even if they themselves were not religious. The results suggest that religion plays a particularly important role in promoting the prosocial norms and values that motivate helping strangers.