This working paper maps the web of international and regional instruments and mechanisms that together make up the legal framework relevant to the phenomenon of migration-related detention, or the deprivation of liberty of non-citizens because of their status. This effort serves a number of purposes: First, it demonstrates the broad expanse of international instruments, above and beyond the core human rights conventions, that have provisions applicable to the rights of detained migrants. Second, it provides readers with a ready-made handbook for identifying how specific legal instruments and human rights bodies can have relevance to detention situations. Lastly, this legal mapping endeavor serves as a preliminary stage in the effort by the Global Detention Project to build a database aimed at measuring state compliance with international obligations.