This study examined the within- and cross-language metalinguistic contribution of three components of metalinguistic awareness (i.e., phonological awareness, morphological awareness, and syntactic awareness) to reading comprehension in monolingual Chinese-speaking children from Mainland China (n = 190) and English–Chinese bilingual children from Singapore (n = 390). Moreover, the effect of home language use on the relationship between metalinguistic awareness and reading performance was investigated. For monolingual children, hierarchical regression analyses revealed that after partialing out the effects of age, nonverbal intelligence, and oral vocabulary, syntactic awareness uniquely predicted 7%–13% of the variance in reading comprehension measures, whereas this relationship was not observed between morphological awareness and reading comprehension. For the bilingual children, within-language regression analyses revealed that English/Chinese morphological awareness and syntactic awareness both contributed significantly to English/Chinese reading measures over and above vocabulary and phonological awareness. Cross-linguistically, structure equation modeling results demonstrated that the bilingual children’s English and Chinese metalinguistic awareness were closely related and jointly supported reading comprehension in both languages, thus lending support to Koda’s transfer facilitation model. Furthermore, home language use was found to contribute to the bilingual children’s reading proficiency via its impact on metalinguistic awareness. The paper concludes with a discussion of the policy and pedagogical implications that can be drawn from these findings.