The mechanisms underlying socioeconomic disparities in children’s reading skills are not well understood. This study examined associations among socioeconomic background, home linguistic input, brain structure, and reading skills in 5-to-9-year-old children (N = 94). Naturalistic home audio recordings and high-resolution, T1-weighted MRI scans were acquired. Children who experienced more adult–child conversational turns or adult words had greater left perisylvian cortical surface area. Language input mediated the association between parental education and left perisylvian cortical surface area. Language input was indirectly associated with children’s reading skills via left perisylvian surface area. Left perisylvian surface area mediated the association between parental education and children’s reading skills. Language experience may thus partially explain socioeconomic disparities in language-supporting brain structure and in turn reading skills.