Reine Adélaïde Sophie Alapini-Gansou is the first Beninese woman to serve on the bench of the International Criminal Court (ICC). Born in Abidjan, Côte d’Ivoire, Alapini- Gansou started her primary education in Libreville, Gabon, before completing it in Ouidah in Benin in 1968. She continued her studies at the Catholic Cours Secondaire Sainte Jeanne d'Arc d’Abomey and finished her secondary education at the Lycée Mathieu Bouké in Parakou, where she obtained her Baccalaureate in Literature in 1978. She studied law at the Faculty of Law and Political Sciences, National University of Benin.

In 1986, Alapini-Gansou was admitted to the bar in Benin and has since been involved in issues relating to human rights. Through her work at the Women’s Legal Aid Center of the WiILDAF network, Alapini-Gansou provided legal and judicial assistance to many in various courts and tribunals in Benin. She was also a lawyer for the Association of Lawyers without Borders(ASF) as part of the "Justice for All in Rwanda" project in 2001. It was also in 2001 that her career in teaching and research began at the Faculty of Law and Political Science and the Faculty of Health Sciences at the University of Abomey- Calavi.

From 2005 to 2017, she was a Commissioner of the African Commission on the Human and Peoples’ Rights. She served as the president of the Commission from 2009 to 2011. She served as a Special Rapporteur on Human Rights Defenders in Africa at three different periods in 2005, 2007 to 2012 and in 2017. In 2012, she was appointed a member of the Permanent Court of Arbitration of the United Nations in The Hague. A year later, Alapini-Gansou established the Fondation défenseurs d’Afrique FDDA (Foundation Defenders of Africa) with the support of the African Human Rights Defenders’ Network.

In 2015, Alapini-Gansou was registered on the International Criminal Court's list of counsel until she was elected as a judge of the court in 2017 – a position she holds to date. Since 9 March 2018, when she was sworn into office, Alapini-Gansou has been serving as a judge in the Pre-Trial and Trial Chambers.