This study explored longitudinal associations between early shared reading at 2 to 3 years of age and children’s later academic achievement. It examined the mediating role of children’s vocabulary and early academic skills, and the moderating effects of family’s socioeconomic status. Data were drawn from the Longitudinal Study of Australian Children (n = 4,768). Academic achievement was assessed at 8 to 9 years of age via standardized national test scores of literacy and mathematics achievement. Results indicated that early shared reading was associated with children’s academic achievement directly and indirectly through receptive vocabulary and early academic skills. Also, the frequency of early shared reading predicted the outcome measures, over and above other home learning activities. Associations were stronger among low and middle socioeconomic status groups compared to the high socioeconomic status group. We conclude that shared reading offers unique opportunities for adults to teach young children new words and concepts.