Slovak is a West Slavic language of the Czech–Slovak group, written in Latin script. It is part of the Indo-European language family, and is one of the Slavic languages, which are part of the larger Balto-Slavic branch. Spoken by approximately 5 million people as a native language, primarily ethnic Slovaks, it serves as the official language of Slovakia and one of the 24 official languages of the European Union.

The West Slavic languages are a subdivision of the Slavic language group. They include Polish, Czech, Slovak, Kashubian, Upper Sorbian and Lower Sorbian. The languages have traditionally been spoken across a mostly continuous region encompassing the Czech Republic, Slovakia, Poland, the westernmost regions of Ukraine and Belarus, and a bit of eastern Lithuania. In addition, there are several language islands such as the Sorbian areas in Lusatia in Germany, and Slovak areas in Hungary and elsewhere.