Our actions and decisions are regularly influenced by the social environment around us. Can socialcues be leveraged to induce curiosity and affect subsequent behavior? Across two experiments, we show that curiosity is contagious: the social environment can influence people’s curiosity about the answers to scientific questions. Participants were presented with everyday questions about science from a popular on-line forum, and these were shown with a high or low number of up-votes as a social cue to popularity. Participants indicated their curiosity about the answers, and they were given an opportunity to reveal a subset of those answers. Participants reported greater curiosity about the answers to questions when the questions were presented with a high (vs. low) number of up-votes, and they were also more likely to choose to reveal the answers to questions with a high (vs. low) number of up-votes. These effects were partially mediated by surprise and by the inferredusefulness of knowledge, with a more dramatic effect of low up-votes in reducing curiosity than of high up-votes in boosting curiosity. Taken together, these results highlight the important role social information plays in shaping our curiosity.