Bosnian is the standard variety of the Serbo-Croatian language mainly used by Bosniaks. It is one of the three official languages of Bosnia and Herzegovina; a co-official language in Montenegro; and an officially recognized minority language in Croatia, Serbia, North Macedonia and Kosovo.

Bosnian uses both the Latin and Cyrillic alphabets, with Latin in everyday use. It is notable among the varieties of Serbo-Croatian for a number of Arabic, Persian and Ottoman Turkish loanwords, largely due to the language's interaction with those cultures through Islamic ties.

Bosnian is based on the most widespread dialect of Serbo-Croatian, Shtokavian, more specifically on Eastern Herzegovinian, which is also the basis of standard Croatian, Serbian and Montenegrin varieties. Therefore, the Declaration on the Common Language of Croats, Serbs, Bosniaks and Montenegrins was issued in 2017 in Sarajevo. Although the common name for the common language remains 'Serbo-Croatian', newer alternatives such as 'Bosnian-Croatian-Serbian' and 'Bosnian-Croatian-Montenegrin-Serbian' have been increasingly utilised since the 1990s, especially within diplomatic circles.

Table of the modern Bosnian alphabet in both Latin and Cyrillic, as well as with the IPA value, sorted according to Cyrillic:

Although Bosnians are, at the level of vernacular idiom, linguistically more homogeneous than either Serbians or Croatians, unlike those nations they failed to codify a standard language in the 19th century, with at least two factors being decisive:

The modern Bosnian standard took shape in the 1990s and 2000s. Lexically, Islamic-Oriental loanwords are more frequent; phonetically: the phoneme /x/ (letter h) is reinstated in many words as a distinct feature of vernacular Bosniak speech and language tradition; also, there are some changes in grammar, morphology and orthography that reflect the Bosniak pre-World War I literary tradition, mainly that of the Bosniak renaissance at the beginning of the 20th century.

The name "Bosnian language" is a controversial issue for some Croats and Serbs, who also refer to it as the "Bosniak" language (Serbo-Croatian: bošnjački / бошњачки, [bǒʃɲaːtʃkiː]). Bosniak linguists however insist that the only legitimate name is "Bosnian" language (bosanski) and that that is the name that both Croats and Serbs should use. The controversy arises because the name "Bosnian" may seem to imply that it is the language of all Bosnians, while Bosnian Croats and Serbs reject that designation for their idioms.^{[citation needed]}

The language is called Bosnian language in the 1995 Dayton Accords and is concluded by observers to have received legitimacy and international recognition at the time. The International Organization for Standardization (ISO), United States Board on Geographic Names (BGN) and the Permanent Committee on Geographical Names (PCGN) recognize the Bosnian language. Furthermore, the status of the Bosnian language is also recognized by bodies such as the United Nations, UNESCO and translation and interpreting accreditation agencies, including internet translation services.