Gnosca is a former municipality in the district of Bellinzona in the canton of Ticino in Switzerland .

On 2 April 2017 the former municipalities of Camorino , Claro, Giubiasco , Gorduno , Gudo , Moleno , Monte Carasso , Pianezzo , Preonzo , Sant'Antonio and Sementina merged into the municipality of Bellinzona.

Gnosca is first mentioned in 1198 as Niosca in the records of Como and the cathedral of Milan . While it is likely that there were earlier settlements, nothing is known about them. An arbitration document of 1202 granted the S. Giovanni church and the church of SS Maurizio e Carpoforo in Gnosca Castle to Como. The parish church of St.