This article reviews research on the typical development of joint attention and challenges that infants and toddlers with autism experience in achieving this milestone. We define joint attention as coordinating attention to an event or object with another individual, sharing interest and social engagement, and showing an understanding that the partner is sharing the same focus. Conceptual frameworks for understanding joint attention are organized around three theoretical perspectives: cognitive-perceptual, language, and social-affective. Several intervention models are explored for their applicability to promoting joint attention in very young children. Finally, future research needs related to joint attention in early intervention are described.