This systematic review aims to take stock of the current knowledge regarding the possible processes, challenges, favourable conditions, and potential for change involved in translanguaging within and across learning settings in the case of multilingual children with a migration background engaged in disciplinary content learning. This study includes 94 publications identified and selected following the PRISMA guidelines. The results point towards seven constitutive and leveraging processes involved in translanguaging. Constitutive processes refer to processes through which translanguaging practices can be enacted (i.e., combining linguistic features attributed to different named languages; employing semiotic features multimodally; translating; comparing). Leveraging processes are processes through which such practices can be promoted (i.e., collaborating; brokering; designing a multilingual linguistic landscape). Furthermore, both challenges to and favourable conditions for translanguaging in in-school and out-of-school settings are linked to efforts to maintain and challenge the prevalent monolingual norm at the level of policies, institutions, educators, children, and caregivers. Finally, building on a boundary-work lens, we show that translanguaging involves significant potential for change, establishing continuity across learning settings for multilingual children with a migration background; however, this continuity emerges in a dynamic interplay with discontinuities for institutional settings and even children themselves.