We present a meta-analysis of cross-linguistic transfer of oral language (vocabulary and listening comprehension), phonology (decoding and phonological awareness) and reading comprehension. Our findings show a small meta-correlation between first (L1) and second (L2) oral language and a moderate to large correlation between L1 and L2 phonological awareness and decoding. This is interpreted in terms of the complexity of oral language compared with phonological awareness and decoding, where the limited number of letter–sound combinations are easier to learn. There were also large variations in the L1–L2 correlations for all language domains. The variation of decoding was moderated by writing system and instructional language. Further, the meta-correlation between L1 decoding and L2 reading comprehension was small to moderate, and decreased reliably with age, while the correlation between L1 oral language and L2 reading comprehension was close to 0. Overall, we argue that the results can be explained from both interdependence and contrastive perspectives.