Besazio (Besasc in lombard) is a municipality in the district of Mendrisio in the canton of Ticino in Switzerland . On 14 April 2013, the former municipalities of Besazio, Ligornetto and Meride merged into the municipality of Mendrisio.

Besazio was first mentioned in 1335 as Besatio. In 15th to 18th centuries, it was called Besaccio. A settlement in this area was first mentioned in 1254, but the area has been settled since ancient times, as Roman era and Early Middle Ages objects indicate. In 1335, it was mentioned as part of the Pieve of Riva San Vitale .