As defined by the UN Special Rapporteur on human rights defenders, a human rights defender (HRD) is “a person who, individually or with others, acts peacefully to promote or protect human rights in accordance with the UN Declaration on Human Rights Defenders.”1 Because of their human rights engagement, HRDs face several risks, including prosecution, arbitrary arrest and detention.2 Censorship by detention is the use by repressive governments of arbitrary detention as a tool to obstruct the defence of human rights, limit civic activism and silence dissent. When governments arbitrarily detain HRDs, they deprive communities of their boldest voices, leaving them more exposed to violations, and send a chilling message to the entire civil society, raising the cost of legitimate human rights defence. Although the phenomenon of censorship by detention is part of a broader trend of closing civic space that has been growing over the past decade, and as much as the detention of HRDs has been a continuous challenge in the defence of human rights across geographies, there has been no sufficient documentation of arbitrary detention of HRDs on a global scale in the past. The lack of data on the number and profiles of HRDs arbitrarily detained poses a major challenge in assessing the magnitude of the phenomenon and its impact on the achievement of the Sustainable Development Goals (SDGs).3 In addition, when cases go unnoticed, governments have a free hand to subject HRDs to torture and other ill-treatment while in detention, and to perpetrate yet more violations against other defenders. In December 2024, SOS-Defenders was launched.4 This collective platform aims to document cases of HRDs arbitrarily detained worldwide and to foster joint action among civil society organisations (CSOs) and other partners for their liberation. The initiative sees the participation of local and international HRD-protection organisations, working together to counter arbitrary detention and reaffirm the right to defend human rights.5 During the first year, SOS-Defenders documented 444 cases of HRDs arbitrarily detained in 17 pilot countries.6 For some HRDs, detention had begun in 2024. For others, it had started, and in some cases even ended, earlier. 420 cases were published on the platform, while 24 were kept confidential to preserve the safety of the HRDs involved. This report presents the data collected with reference to HRDs whose arbitrary detention started or ended between 1st January and 31st December 2024. 1. At: https://srdefenders.org/who-is-an-hrd/who-is-a-human-rights-defender/ 2. The Working Group on Arbitrary Detention clarifies that “‘Arbitrariness’ is not to be equated with ‘against the law’, but must be interpreted more broadly to include elements of inappropriateness, injustice, lack of predictability and due process of law”. At: https://www.ohchr.org/ en/about-arbitrary-detention 3. SDG Indicator 16.10.1 refers, among other violations, to the “Number of verified cases of […] arbitrary detention and torture of […] human rights advocates in the previous 12 months”. 4. At: https://sos-defenders.org/en/. 5. The full list of partners is available at: https://sos-defenders.org/en/page/7hg5udz2vs9/about 6. Pilot countries were: Bahrain; Belarus; Cambodia; Egypt; Ethiopia; Guatemala; Iran; Jordan; Kuwait; Nicaragua; Qatar; Russian Federation; Saudi Arabia; Tunisia; Ukraine; United Arab Emirates; and Yemen. 7