Understanding the factors that promote the development of generosity has both theoretical and practical importance. This study examines one potential influence: overheard conversations that contain evaluative statements about the behavior of others that were described as widely shared opinions. In Study 1 (N = 120), younger (mean age 4.1 years old) and older (mean age 5.9 years old) participants overheard two adults discuss a target child's act of generosity, and in a between‐subjects manipulation, the conversation included either praise for the target child, or criticism. Participants in the older group were more likely to behave generously on a distribution task if the overheard conversation involved praise rather than criticism, but the participants in the younger group showed no such effect. Study 2 (N = 150) and Study 3 (N = 60) were preregistered follow‐up studies that included older children only (a 5‐year‐old group). Study 2 showed that children were again more likely to share after overhearing a conversation in which an individual who behaved generously was described in favorable terms, and the same effect was seen when the overheard conversation involved criticism of an individual who did not share. The procedure of Study 3 matched that of Study 1, except the distributions were made in private, and the overheard conversation effect was seen once again. These findings suggest that by age 5, children can use information they hear about individuals who are not present to guide their own behavior, and that overheard evaluative comments can promote generosity.