Kádár ([ˈkaːdaːr]; Hungarian for "cooper") is a Hungarian surname which may refer to:
Ján Kadár, Slovak-Hungarian film director
János Kádár (1912–1989), Hungarian politician, top leader during the communist era
Flóra Kádár (1928–2002), Hungarian actress
Kálmán Kádár, Romanian water polo player of Hungarian descent
Matthias Kadar, a composer of German-Hungarian descent
Tamás Kádár, Hungarian footballer
Zoltán Kádár, Romanian footballer of Hungarian descent