Around the world, women, girls and gender-diverse people play a crucial role in promoting and protecting the rights of people on the move. They do so in numerous ways—such as by rescuing those in distress at land and sea and accompanying migrants on dangerous journeys. Some provide shelter, transport, healthcare, education, legal aid and integration support to people at different stages of migration. Others document human rights violations and advocate for laws, policies and practices that protect the rights of migrants, refugees and stateless persons. However, migrant women human rights defenders face significant risks as they do so, such as stigmatization, criminalization, surveillance, physical attacks and sexual and gender-based violence from both state and non-state actors. Women human rights defenders who are migrants themselves, especially those in an irregular situation, often face higher risks due to their migration status, such as arrest, detention, deportation and refoulement. They may also be subject to torture or cruel, inhuman and degrading treatment; some have been killed or forcibly disappeared. It is critical for states to respect, protect and fulfil the rights of migrant women human rights defenders. This policy brief outlines measures that states can take to create an enabling environment for the defence of human rights and to secure the rights of women, girls and gender-diverse people at all stages and in all types of migration so that they can defend their own rights and the rights of others.