Humans make decisions about when and with whom to cooperate based on their reputations. People either learn about others by direct interaction or by observing third-party interactions or gossip. An important question is whether other animal species, especially our closest living relatives, the nonhuman great apes, also form reputations of others. In Study 1, chimpanzees, bonobos, orangutans, and 2.5-year-old human children experienced a nice experimenter who tried to give food/toys to the subject and a mean experimenter who interrupted the food/toy giving. In studies 2 and 3, nonhuman great apes and human children could only passively observe a similar interaction, in which a nice experimenter and a mean experimenter interacted with a third party. Orangutans and 2.5-year-old human children preferred to approach the nice experimenter rather than the mean one after having directly experienced their respective behaviors. Orangutans, chimpanzees, and 2.5-year-old human children also took into account experimenter actions toward third parties in forming reputations. These studies show that the human ability to form direct and indirect reputation judgment is already present in young children and shared with at least some of the other great apes.