The Polish alphabet derives from the Latin script, but includes certain additional letters formed using diacritics. The Polish alphabet was one of three major forms of Latin-based orthography developed for Slavic languages, the others being Czech orthography and Croatian orthography, the latter being a 19th-century invention trying to make a compromise between the first two. Kashubian uses a Polish-based system, Slovak uses a Czech-based system, and Slovene follows the Croatian one; the Sorbian languagesblend the Polish and the Czech ones.

The diacritics used in the Polish alphabet are the kreska (graphically similar to the acute accent) in the letters ć, ń, ó, ś, ź and through the letter in ł; the kropka (superior dot) in the letter ż, and the ogonek (“little tail”) in the letters ą, ę. The letters q, v, x are often not considered part of the Polish alphabet; they are used only in foreign words and names.