Legal Sources in Business and Human Rights engages with some evolving trends that are currently affecting the international and EU law sources in the field of Business and Human Rights. Three main dynamics are detected and explored: the emergence of international legal obligations that are also binding on corporations (Part I); the growing participation of corporations in traditional international standard-setting and law-making processes and, in parallel, the emergence of atypical and heterogeneous law-making processes (Part II); the formal or substantive hardening of originally soft normative standards, through a multi-layered and multi-player law-making process (Part III). Interestingly, these trends concur to mitigate States’ reluctance to accept binding rules in this field, and to strengthen the effectiveness of soft international regulation.