Mendrisio is a municipality in the district of Mendrisio in the canton of Ticino in Switzerland.
Mendrisio is the seat of the Accademia di Architettura of the university of Italian-speaking Switzerland (USI).
The municipality was boosted in size on 4 April 2004 when it incorporated the former municipality of Salorino. On 5 April 2009 it incorporated the former municipalities of Arzo, Capolago, Genestrerio, Rancate and Tremona. On 14 April 2013 the former municipalities of Besazio, Ligornetto and Meride merged into the municipality of Mendrisio.
Mendrisio is served by Mendrisio railway station.
The district of Mendrisio (also called Mendrisiotto) is the southernmost district of canton of Ticino and of Switzerland. To its north lies the district of Lugano. It is surrounded on the other three sides by Italy: to the east and south by the province of Como, and to the west by the province of Varese. It has a population of (as of ).