As adults, we remember information better that is related to ourselves compared to similar information without self-reference. This self-reference bias is well-documented in both adults and children, but its developmental origins are unknown. Here, we hypothesized that its emergence should be associated with the development of a self-concept in the second year of life. We presented 18-month-old infants with a sequence of novel objects that were assigned either to them, or to a puppet. Infants were then tested on their memory for the objects by presenting them with an image of each of the objects, alongside an image of a similar but modified version of the same object. As an index of self-concept emergence, infants were also tested for mirror self-recognition. 18-month-olds who passed the mirror self-recognition test remembered objects assigned to them better than those assigned to the puppet, and this result was replicated in a second study with older infants. In contrast, 18-month-olds who did not evidence mirror self-recognition only remembered the objects assigned to the puppet, but not the objects assigned to themselves. This suggests that the self-reference effect emerges with the development of self-concept in the second year of life. However, prior to the emergence of a self-concept, infants instead exhibit an other-reference effect. We suggest that prioritizing information relevant to others is adaptive given young infants’ heavy dependence on others, but that, with the emergence of a self-concept, infants transition to prioritizing self-relevant information.