“Best interest” is a principle that plays a central role in judicial decisions about child welfare and custody determinations. It figures prominently in court cases involving children in the United States foster care system, as well as child migrants applying for legal residency status. This article explores best interest as a site of translation, one that enables social workers and legal actors to make seemingly value‐free legal decisions that, in fact, codify a perception that the United States is necessarily the best place for all children to be raised, regardless of their specific circumstances.