West Slavic language belonging to the Lekhitic subgroup and closely related to Czech (Czech language), Slovak (Slovak language), and the Sorbian (Sorbian languages) languages of eastern Germany; it is spoken by the majority of the present population of Poland.

The modern literary language, written in the Roman (Latin) alphabet, dates from the 16th century and was originally based on the dialects of the area around Poznań, in western Poland. The first written Polish consists of a list of names in the Papal Bull issued in 1136 by Pope Innocent II to the archbishop of Gniezno; the oldest recorded sentence is a gloss translating a quotation in a document from 1270. Extant manuscripts containing any appreciable amount of connected Polish text date back no earlier than the 14th century.

Polish contains a great number of words borrowed from Latin, Czech, German, Belarusian, and Ukrainian and also some words from Italian, French, and English. Along with the other West Slavic languages, it has a fixed stress accent. In contrast to the others, however, the language has nasalized vowels (spelled ę and ą), indirectly continuing the nasalized vowels of early Slavic. Among the major dialects are Great Polish and Pomeranian, Silesian, Little Polish, and Mazovian. Kashubian (Cassubian), often classified as a Polish dialect, is, historically, a separate language.