César Sivo is a human rights lawyer in Mar de Plata, Argentina. Since 1989, he has been defending the rights of minorities and vulnerable groups, by providing legal aid and visibilising their situation. Since 1997 he has participated in the legal proceedings of Memory, Truth and Justice for the crimes against humanity committed during the Argentinian military dictatorship (1976-1983), gathering evidence to open the cases before the National Audience of Spain and, afterwords, in the trials in Mar del Plata. He has also provided legal representation to the Assembly if the Guarani People - ITIKA GUASU in Bolivia. César is a member of Asamblea Permanente por los Derechos Humanos – APDH (Permanent Assembly for Human Rights), an organisation founded in 1975 by people from the most diverse social, political, intellectual, trade union and religious sectors in Argentina in response to the violence and widespread human rights violations taking place during the dictatorship.
In August 2016, several human rights lawyers, including César Sivo, working on the legal cases on crimes against humanity committed during the Argentinian military dictatorship received threats and suffered harassment and break-ins in their offices and homes. In the past, smear campaigns, threats and attacks against him intensified at key moments of trials for crimes against humanity in which César Sivo played a key role. Close relatives of the human rights defender have been harassed through social media and unknown individuals twice broke into and took confidential information from his wife's legal office.