Research Findings: The present study examined the relation between socioeconomic status (SES) and Chinese children's development of English as a second language in Hong Kong, and whether the home literacy environment (HLE) was an important mediator. Participants were 237 children (110 girls, M[subscript age] = 47.38 months, SD[subscript age] = 3.66) and one of their caregivers. Children were assessed on phonological awareness, receptive vocabulary, expressive vocabulary, and letter knowledge. Information on HLE (i.e. shared reading, extratextual talk, direct teaching, play and media-based activities, and literacy resources) was obtained via a caregiver questionnaire. Findings revealed significant SES differences in all aspects of HLE, as well as in children's English receptive vocabulary, expressive vocabulary, and letter knowledge. HLE was differentially related to children's English skills, suggesting the mediating effect of HLE in the relation between SES and Chinese children's English skills. Practice or Policy: Findings from this study highlight the features of HLE that can best support children's second language development. The results can also inform the design of family interventions and policies aimed at reducing educational disparities.