Based upon the ecological perspective and the social cognitive theory, this study examined the role of reading self-efficacy in the associations of contextual factors with reading achievement by establishing an educational ecology of reading. The model included student factors, student/home factors, student/school factors, and school factors of reading. These contextual factors were hypothesised as predictors of reading self-efficacy, which was, in turn, the predictor of reading achievement. The Canadian data of the Progress in International Reading Literacy Study 2016 with 18,624 Grade 4 students from 926 schools were analysed with multilevel structural equation modelling. Results showed that most student- and school-level factors significantly predicted reading self-efficacy, which in turn significantly predicted reading achievement. Home resources for learning and school climate factors showed the strongest associations with reading. The theoretical and practical implications of our findings were discussed.