Sant`Abbondio is a former municipality in the district of Locarno in the canton of Ticino in Switzerland.

On 25 April 2010, the former municipalities of Caviano , Contone , Gerra Gambarogno , Indemini , Magadino , Piazzogna , San Nazzaro, Sant'Abbondio and Vira Gambarogno merged in the new municipality of Gambarogno.

Sant'Abbondio is first mentioned in 1192 as Sancto Abundio.

According to a document from 1358, the settlements of Martignoni de Ronco, Ronco di Sopra, Scimiana, Calgiano, Caviano and Scaiano had already grown up around the church of SS Abbondio e Andrea. The church itself is first mentioned in 1364. It was part of the parish of Vira, when it became the center of an independent parish.