This study examined the crosslinguistic sharing of morphological awareness (MA) in biliteracy development. The analysis included 34 correlational studies with 41 independent samples (N = 4,104). Correlational coefficients were meta-analyzed, yielding four main findings: (a) the correlation between first language (L1) and second language (L2) MA was small (r = 0.30); (b) the interlingual correlations between L1 MA and L2 word decoding and between L1 MA and L2 reading comprehension were both small (r = 0.35, 0.39, respectively); (c) the intralingual correlations between L2 MA and L2 word decoding and between L2 MA and L2 reading comprehension were both moderate (r = 0.46, 0.52, respectively); and (d) MA measurement type and age were significant moderators. Our review suggests that there is a need for future research to align the definition and measurement of MA.