Balerna is a municipality in the district of Mendrisio in the canton of Ticino in Switzerland.

Balerna is first mentioned in 1115 as Barerna. In 844 and 865, the monastery of S. Ambrogio in Milan purchased land in the concilium of Castel S. Pietro which would have included Balerna. In the 12th century some decimani (tithe collectors) and the monastery of S. Abbondio in Como owned land and associated rights in Balerna.

By no later than the 12th century, Balerna was as the center of a pieve, which encompassed the area that is now the district of Mendrisio except for Chiasso (which was part of the pieve of Zezio) and some areas of the Pieve of Riva San Vitale. Balerna, together with Riva and Uggiate, formed a consorzio (a common property group) in the 12th century. Politically the municipalities of Chiasso, Boffalora, Pedrinate, Seseglio, Novazzano, Coldrerio, Villa, Castel San Pietro, Vacallo and the Valle di Muggio part of the Pieve of Balerna.

Starting in the 9th century Balerna belonged to the count of Seprio. In the 13th century it was under the city of Como, and later under the Bishop of Como. In 1335 under the rule of the Visconti of Milan, then under Franchino Rusca. In 1412 it came to the Duke of Milan, who completely separated it from Como in 1416. Balerna was now ruled by a Podestà, who resided in Mendrisio, but had his court in Balerna. In the following period it was owned by a large number of rulers: the Rusca family (1416–32), the Sanseverino family, the Golden Ambrosian Republic, the Schliessler family and then the Sforza family. In 1475, the Sforzas separated Balerna administratively from Mendrisio. In 1499 it passed into the hands of Count Bartolomeo Crivelli, but it was occupied in the same year by the French. In 1512 they were followed by the Swiss Confederation, who combined it with Mendrisio into a bailiwick. As part of the bailiwick, Balerna was able to retain its privileges. Until 1573 the bailiff had a court in Balerna. He had two plebani representing him at Balerna and two reggenti at Mendrisio. In 1798 it was supposed to become part of the Cisalpine Republic, but it, instead, wanted to be part of Switzerland. The decree of Aarau on 30 May 1798 combined it with Mendrisio as part of the Helvetic Republic.

In 1910, the Mendrisio electric tramway opened, linking a northern terminus in Riva San Vitale with Capolago, Mendrisio, Balerna and Chiasso. The section of the line in Balerna closed in 1950 and was replaced by a bus service.

Balerna has an area, as of 1997^[update], of 2.57 square kilometers (0.99 sq mi). Of this area, 1.01 km² (0.39 sq mi) or 39.3% is used for agricultural purposes, while 0.16 km² (0.062 sq mi) or 6.2% is forested. Of the rest of the land, 2 km² (0.77 sq mi) or 77.8% is settled (buildings or roads), 0.04 km² (9.9 acres) or 1.6% is either rivers or lakes and 0.03 km² (7.4 acres) or 1.2% is unproductive land.

Of the built-up area, industrial buildings made up 15.2% of the total area while housing and buildings made up 25.3% and transportation infrastructure made up 30.7%. Power and water infrastructure as well as other special developed areas made up 1.9% of the area while parks, green belts and sports fields made up 4.7%. Out of the forested land, 2.3% of the total land area is heavily forested and 3.9% is covered with orchards or small clusters of trees. Of the agricultural land, 13.6% is used for growing crops and 25.3% is used for alpine pastures. All the water in the municipality is flowing water.

The municipality is located in the Mendrisio district. The municipal area, crossed by transit axes of the Gotthard line, also includes the settlements of Caslaccio, Mercole, S.Antonio, Bisio, Pontegana, Passeggiata.