Human rights law is supposed to provide comprehensive protection for the fundamental rights of all individuals. However, this universalist aspiration is heavily qualified when it comes to migrants with irregular status. Various factors play a role in limiting the reach of human rights law in this context, including (i) ‘external’ constraints such as states resisting giving effect to certain international human rights guarantees; (ii) ‘internal’ factors such as a dilution of the relevant standards when it comes to applying them to irregular migrants; and (iii) the underdevelopment of human rights law in certain key respects. However, despite these limitations, human rights standards can still provide an important platform for challenging exclusionary policies directed against irregular migrants. Irregular migrants may have fewer rights than others, but they are not ‘rightless’—and the universalist aspirations of human rights law can still be leveraged to challenge their treatment.