Italian or lingua italiana is a Romance language. Italian is by most measures, together with the Sardinian language, the closest tongue to vulgar Latin of the Romance languages. Italian is an official language in Italy, Switzerland, San Marino, Vatican City and western Istria (in Slovenia and Croatia). It used to have official status in Albania, Malta and Monaco, where it is still widely spoken, as well as in former Italian East Africa and Italian North Africa regions where it plays a significant role in various sectors. Italian is also spoken by large expatriate communities in the Americas and Australia. It has official minority status in Bosnia and Herzegovina, Croatia, Slovenia and Romania. Many speakers are native bilinguals of both standardized Italian and other regional languages. Italian is a major European language, being one of the official languages of the Organisation for Security and Cooperation in Europe and one of the working languages of the Council of Europe. It is the third most widely spoken first language in the European Union with 69 million native speakers (13% of the EU population) and it is spoken as a second language by 16 million EU citizens (3%). Including Italian speakers in non-EU European countries (such as Switzerland and Albania) and on other continents, the total number of speakers is around 90 million.

Italian was adopted by the state after the Unification of Italy, having previously been a literary language based on Tuscan as spoken mostly by the upper class of Florentine society. Its development was also influenced by other Italian languages and to some minor extent, by the Germanic languages of the post-Roman invaders. The incorporation into Italian of learned, or "bookish" words from its own ancestor language, Latin, is arguably another form of lexical borrowing through the influence of written language and the liturgical language of the Church. Throughout the Middle Ages and into the early modern period, most literate Italian speakers were also literate in Latin; and thus they easily adopted Latin words into their writing—and eventually speech—in Italian. Its vowels are the second-closest to Latin after Sardinian. Unlike most other Romance languages, Italian retains Latin's contrast between short and long consonants. As in most Romance languages, stress is distinctive.

Italian is the main working language of the Holy See, serving as the lingua franca (common language) in the Roman Catholic hierarchy as well as the official language of the Sovereign Military Order of Malta. Italian is known as the language of music because of its use in musical terminology and opera. Its influence is also widespread in the arts and in the luxury goods market. Italian has been reported as the fourth or fifth most frequently taught foreign language in the world.

Throughout Italy, regional variations of Standard Italian, called Regional Italian, are spoken. In Italy, almost all Romance languages are spoken as the vernacular—other than standard Italian and distantly-related, non-Romance languages spoken in border regions or among immigrant communities—are often imprecisely called "Italian dialects", even though they are quite different, with some belonging to different branches of the Romance language family. The only exceptions to this are Sardinian, Ladin and Friulian, which are officially recognized as distinct minority languages by the law. On the other hand, Corsican (a language spoken on the French island of Corsica) is closely related to Tuscan, from which Standard Italian derives and evolved.