Many challenges faced by humans require large-scale cooperation for communal benefits. We examined what motivates such cooperation in the context of social distancing and mask wearing to reduce the transmission intensity of the novel coronavirus (COVID-19). We hypothesized that collectivism, a cultural variable characterizing the extent that individuals see themselves in relation to others, contributes to people’s willingness to engage in these behaviors. Consistent with preregistered predictions, across three studies (n=2864), including a U.S. nationally representative sample, people’s collectivist orientation is positively associated with intentions, positive beliefs, norm perceptions, and policy support for the preventive behaviors. In separate analyses at the country level (n=69 countries), more collectivist countries demonstrated lower growth rate in both COVID-19 confirmed cases and deaths. Together, these studies demonstrate the positive role of collectivism at the individual- and country-level in reducing COVID-19 transmission, and highlight the need to consider culture in public health policies and communications.