Sonogno is a village and former municipality in the district of Locarno in the canton of Ticino in Switzerland. It is located in Valle Verzasca. On 17 October 2020 the former municipalities of Vogorno, Sonogno, Corippo, Brione (Verzasca) and Frasco merged to form the new municipality of Verzasca.

The Valle Verzasca is a valley in the Locarno district of the canton of Ticino, Switzerland. It comprises the municipalities of Mergoscia, Vogorno, Corippo, Lavertezzo, Brione, Gerra, Frasco, and Sonogno. As of 2004, the total population is 3,200. It is the most central valley of Ticino, and none of the passes out of the valley cross cantonal or national borders. The valley is formed by the river Verzasca and is situated between the Leventina and the Maggia and culminates at Pizzo Barone.