Young children tend to behave more generously when their actions are identified than when they are anonymous, yet we know little about the cognitive foundations required for anonymity to impact generosity. In three studies we examined Canadian children's understanding of anonymity and its impact on sharing in anonymous and identified contexts. Study 1 assessed whether 3- and 5-year-old children (N = 100, 51 female) understood anonymous and identified sharing, and whether age-related changes in their understanding corresponded to sharing behavior. We found that understanding of anonymity improved with age, but anonymity did not influence sharing. Study 2 assessed 5-year-old children's (N = 60, 30 female) judgments about how others would share in these contexts and their preferences for receiving donations from identified or anonymous donors. We found that children preferred to receive from identified donors and believed that identified donors were more generous. Study 3 assessed whether 5-year-old children (N = 60, 30 female) preferred to share as anonymous or identified donors themselves, and whether their choice influenced sharing behavior. We found that while participants preferred to share as identified donors, this choice did not influence sharing. Overall, our findings suggest that although 5-year-old Canadian children have a robust understanding of the implications of anonymous and identified sharing, this understanding is not sufficient to motivate increased generosity.