Mario Annoni studied Political Science and Law at the universities of Lausanne and Geneva, and was licensed as a lawyer in Bern. After chairing the Regional Court of La Neuveville, Courtelary and Moutier, he was elected to the Bern State Council in 1990, where he headed the Department of Justice, Communes and Churches from 1990 to 1998, and the Department of Public Education and Culture from 1998 to 2006. He chaired the Swiss cultural foundation Pro Helvetia between 2006 and 2013. Mario Annoni currently heads the «Avenir Berne romande» project.
Foundation Istituto svizzero di Roma e Milano (President of the Foundation Board); Société des Forces Electriques de la Goule, Saint-Imier (Chairman); Ecole de musique du Jura bernois, Saint-Imier (Chairman); Abegg-Stiftung, Riggisberg (Member of the Foundation Board); Stiftung Rebhaus Wingreis, Twann (President of the Foundation Board); Fondation du Musée de la Vigne du bord du Lac de Bienne, La Neuveville (President of the Foundation Board); Société des Forces Motrices du Châtelot (Member of the Board of Directors).