Joint attention, or shared attention to an object or event, is a pivotal skill for the development of social interactions and social communication. Joint attention typically develops in natural contexts within the first year of life. Children with autism spectrum disorder (ASD) and related developmental disabilities often experience difficulty developing joint attention. Clinical interventions to increase joint attention exist. However, there are limited studies investigating methods to incorporate joint attention interventions in inclusive preschool classrooms with peers as social partners. For young children in preschool settings, peer-mediated social skills interventions reflect natural contingencies and may promote generalization. In this study, we employed a single-case multiple baseline across child–peer dyads design to evaluate the effects of a peer-mediated joint attention intervention for children with or at risk for ASD on response to joint attention (RJA) from peer bids and initiations of joint attention (IJA) from target children with ASD. The intervention included direct instruction with a social narrative to teach three peers to initiate bids for joint attention to measure target children’s responses. Target children later received the same direct instruction to increase IJA to same-age-peers. Results indicate increased target child RJA and IJA to peers. Limitations and implications for research and practice are discussed. (author abstract)