Berzona is first mentioned in 1265 as Berzona.
The village section of Seghelina is located directly on the main road, while the main village is above the road. During the Middle Ages it was part of the Squadra of Onsernone.
The church of S. Defendente was built in 1564 and became a parish church when it separated from Loco in 1777. The section of Seghelina has the chapels of Santa Maria (1682) and S. Maria Lauretana (1766). The political municipality was created at the same time as the Canton of Ticino in 1803.
After World War II, much of the village population emigrated and sold their properties to outsiders. Many people who bought houses in Berzona were well known personalities from the arts and culture, such as Alfred Andersch, Golo Mann, Jan Tschichold and Max Frisch. Today, the village is shrinking as few jobs in farming and grazing remain and most of the working population have moved to Locarno.
The historical population is given in the following table: