Human rights defenders (HRDs) are “people who, individually or with others, act to promote or protect human rights in a peaceful manner”.1 Because of their human rights engagement, HRDs face numerous risks, including prosecution, arbitrary arrest and detention.2 Censorship by detention refers to the use of arbitrary detention by repressive governments as a tool to obstruct the defence of human rights, restrict civic activism and silence dissent. Since 2024, the SOS-Defenders initiative has brought together civil society organisations (CSOs) from around the world to document cases of arbitrarily detained HRDs and advance coordinated action for their release. By consolidating data on a single global platform,3 SOS-Defenders provides a more comprehensive understanding of censorship by detention and mobilises collective action to counter it. More than 20 local, regional and international CSOs are currently engaged in the initiative, working together to protect HRDs and uphold the right to defend human rights.4 In 2025, SOS-Defenders continued to strengthen its role as a global repository and action platform on the arbitrary detention of HRDs. Building on the achievements of its initial pilot phase, the initiative expanded its network of partners and broadened its geographic coverage, enabling the publication of more than 500 cases of arbitrarily detained HRDs worldwide since the platform’s launch. Throughout the year, SOS-Defenders partners worked collectively to expose patterns of repression, support advocacy efforts and engage with relevant stakeholders to secure the release of arbitrarily detained HRDs. These efforts contributed to numerous positive outcomes and reinforced the importance of coordinated and sustained collective action to counter censorship by detention. Against a backdrop of shrinking civic space, increasing authoritarian practices and the growing criminalisation of human rights defence, SOS-Defenders also played an active role in international policy discussions aimed at reaffirming the right to defend human rights.5 This report presents data collected on HRDs whose arbitrary detention began or ended between 1 January and 31 December 2025. In doing so, it contributes to the monitoring of Sustainable Development Goal (SDG) Indicator 16.10.1, which measures, among other violations, the annual number of verified cases of arbitrary detention of HRDs.6 1. About human rights defenders, Special Rapporteur on human rights defenders. At: https://www.ohchr.org/en/special-procedures/sr-humanrights-defenders/about-human-rights-defenders 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. At: https://sos-defenders.org/en/ 4. The full list of partners is available at: https://sos-defenders.org/en/page/7hg5udz2vs9/about 5. See, for example, the follow-up paper from the 12th Inter-Mechanisms Meeting. Securing the release of human rights defenders arbitrarily detained. At: https://www.omct.org/site-resources/legacy/12th-IMM-follow-up-paper_FINAL.pdf 6. Indicator 16.10.1 reads: “Number of verified cases of killing, kidnapping, enforced disappearance, arbitrary detention and torture of journalists, associated media personnel, trade unionists and human rights advocates in the previous 12 months”. 7