This factsheet provides an overview of the UN human rights mechanisms, with a particular focus on those most relevant to freedom of religion or belief. The factsheet describes the mandate and composition of the Human Rights Council and its subsidiaries, which include the Universal Periodic Review Working Group, the Special Procedures mandate holders, and factfinding missions. The UN treaty-based mechanisms, such as the Human Rights Committee established by the International Covenant on Civil and Political Rights, are also explained. The factsheet includes examples of engagement with these mechanisms that has advanced religious freedom. Although these bodies have various imperfections and limitations, they nevertheless provide opportunities for advocacy by and collaboration among states and non-governmental organizations (NGOs) working to promote religious freedom internationally.