Swiss Italian (Italian: italiano svizzero, Italian: [itaˈljaːno ˈzvittsero]) is the variety of the Italian language taught in the Italian-speaking area of Switzerland. While this variety is mainly spoken in the canton of Ticino and in the southern part of Grisons (about 270,000 native speakers), Italian is spoken natively in the whole country by about 700,000 people: Swiss Italians, Italian immigrants and Swiss citizens with Italian citizenship.

The Swiss variety of Italian is distinct from the traditional vernaculars of the Italian-speaking area, which are classified as varieties of the Gallo-Italic Lombard language.

Italian, as the third Swiss national language, is spoken in Italian-speaking Switzerland (Ticino and the southern part of Grisons). It is an official language both at the federal level and in the two cantons of Ticino and Grisons.

Italian is also one of the most spoken languages in German-speaking Switzerland, and used as an idiom by Italian immigrants and their children. Italian is also used as a lingua franca between foreign workers of different nationalities, including Portuguese, Spanish, etc.

At the time of post-World War II Italian immigration to Switzerland, Italian was transmitted as a lingua franca in factories and on construction sites to non-Italian ethnic groups of foreign workers who subsequently settled in Switzerland. Italians were the pre-existing majority linguistic group, and the language was easy to learn for Spanish-speaking immigrants, leading to Italian becoming the dominant language among foreign workers. Later, Italian was also acquired by populations of other ethnic groups, for example by Greek speakers or groups from Yugoslavia, encouraged by the greater ease of learning in informal contexts and also by the fact that the knowledge of Italian by German-Swiss and French-Swiss is generally much higher than the knowledge of Italian in Germany or France. Today, the use of Italian as a lingua franca among workers in Switzerland is in decline.

There are some variations between Swiss Italian and the Italian language in Italy. While the use of local minority languages and dialects leads to distinct regional differences within languages, Swiss Italian is generally quite similar to the Italian language in Italy, with differences that are easy to trace and understand. Some Helvetisms have recently been included in the dictionaries of the Italian language. Linguistic misunderstandings between Italians and Swiss Italians are generally rare, but possible.

The presence of calques from French and German means that there are some differences in vocabulary between the standard registers of the Italian language used in Italy and Switzerland. An example would be the words for driving licence: in Italy, it is called a patente di guida but in Swiss Italian, it becomes licenza di condurre, from the French permis de conduire. Another example is the interurban bus: in Italy it would be autobus or corriera but in Switzerland, it is the Autopostale or posta.

Another notable difference is the use of the word germanico to refer to German people, instead of tedesco. However, as in Italy, the word tedesco is used to refer to the German language. In Italy, the word germanico is used in the same sense as the word "Germanic" in English, referring, for example, to Germanic languages in general.