Kazimierz (Polish pronunciation: [kaˈʑimjɛʂ]; Latin: Casimiria; Yiddish: קוזמיר, romanized: Kuzimyr) is a historical district of Kraków and Kraków Old Town, Poland. From its inception in the 14th century to the early 19th century, Kazimierz was an independent city, a royal city of the Crown of the Polish Kingdom, located south of the Old Town of Kraków, separated from it by a branch of the Vistula river. For many centuries, Kazimierz was a place where ethnic Polish and Jewish cultures coexisted and intermingled. The northeastern part of the district was historically Jewish. In 1941, the Jews of Kraków were forcibly relocated by the German occupying forces into the Krakow ghetto just across the river in Podgórze, and most did not survive the war. Today, Kazimierz is one of the major tourist attractions of Krakow and an important center of cultural life of the city.

The boundaries of Kazimierz are defined by an old island in the Vistula river. The northern branch of the river (Stara Wisła – Old Vistula) was filled-in at the end of the 19th century and made into an extension of Stradomska Street connecting Kazimierz district with Kraków Old Town.