This edited collection is the result of an international workshop Brave New Law! Legal Personhood in the New Biosciences, which was held in late August 2018, at the University of Sydney and organized by the Biopolitics of Science Research Network. The workshop brought together 33 scholars from around the world to discuss changes in and transformations of legal personhood considering recent bioscientific developments. The premise of the workshop was that complex issues were emerging in the intersection of law and biology, an area of law that was quickly expanding and displaying highly composite problems that challenge existing legal regimes. Key questions included: What do the new biosciences do to our social, cultural, and legal conceptions of personhood? How does our legal apparatus incorporate new legitimations from the emerging biosciences into their knowledge systems? And what kind of ethical, socio-political, but also scientific consequences are attached to the establishment of such new legalities? By bringing together legal scholars, anthropologists, sociologists, historians, cultural theorists, and political philosophers, the aim of the workshop was to examine these problems by looking at materialities, the posthuman, and the relational in the (un)making of legalities, but also to critically assess the “newness” of these legalities, and to compare them with earlier investigations of natural personhood.