In this paper, we identify culture, particularly collectivist culture, as a new factor that explains variations in corporate social responsibility (CSR) activities across countries and regions. Drawing on the rice theory that links rice and wheat cultivation to collectivist and individualist cultures, we investigate how collectivist culture affects CSR activities. We find that firms located in regions with stronger collectivist cultures have better CSR performance and higher charitable donations, and that this positive relationship is stronger after a natural disaster that increases the social demand for corporate philanthropy. Moreover, we find that the positive effect of collectivist culture on CSR activities is stronger for firms with stronger local ties or that face higher public scrutiny. These findings suggest that firms in regions with stronger collectivist cultures are more responsive to social needs and expectations. Finally, we find that CSR engagements reduce firm risk more effectively in regions with stronger collectivist cultures.