Imagined Racial Laboratories reveals the watermarks of science in the dynamics of racialisation in Southeast Asia, during and after the colonial period. Bringing together a set of critical histories of race sciences, it illuminates the racialised dimensions of colony and nation in the region. It demonstrates that racialisation took — and continues to take — mutable and multiple forms that often connect, perhaps more than differentiate, colonial and national periods across a variety of Southeast Asian settings. Thus, imagined races have contributed as much to the invention of modern Southeast Asia as have other fabled imagined communities.