<p>The current study investigated how independent book reading at home and socioeconomic status (SES) were associated with children’s language and literacy skills within and across their two languages among Spanish and Chinese-English bilingual children. We then explored whether SES moderated the associations between independent book reading frequency and children’s language and literacy skills. Results showed considerable differences between these two groups. While more frequent English independent book reading was associated with better English and Spanish skills for Spanish–English bilinguals, it was only associated with better English skills for Chinese-English bilinguals. More frequent independent book reading in the heritage language was linked to Spanish-English bilinguals’ better skills in both languages, which was not found in Chinese-English bilinguals. Further, SES was positively associated with Spanish-English bilinguals’ skills in both languages. However, SES moderated the association between Chinese independent book reading and Chinese skills for Chinese-English bilinguals, suggesting that independent book reading practices in the heritage language may serve as a protective factor and mitigate the negative impact of low SES on children’s heritage language and literacy development.</p>