Past research has established clear support for the prosocial function of gratitude in improving the well-being of others. The present research provides evidence for another hypothesized function of gratitude: the social alignment function, which enhances the tendency of grateful individuals to follow social norms. We tested the social alignment hypothesis of gratitude in 2 studies with large samples. Using 2 different conformity paradigms, participants were subjected to a color judgment task (Experiment 1) and a material consumption task (Experiment 2). They were provided with information showing choices allegedly made by others, but were allowed to state their responses in private. Supporting the social alignment hypothesis, the results showed that induced gratitude increased private conformity. Specifically, participants induced to feel gratitude were more likely to conform to the purportedly popular choice, even if the option was factually incorrect (Experiment 1). This effect appears to be specific to gratitude; induction of joy produced significantly less conformity than gratitude (Experiment 2). We discuss whether the social alignment function provides a behavioral pathway in the role of gratitude in building social relationships.