| Kálmán Kádár | |
| Full Name: | Kálmán János Kádár |
| Birth Date: | 11 June 1979 |
| Birth Place: | Oradea, Romania |
| Height: | 1.90 m |
| Weight: | 94 kg |
| L/R: | Right |
| Currentnumber: | 12 |
| Nationalyears1: | 2001 - 2012 |
| Nationalteam1: |  Romania |
Kálmán János Kádár (in Hungarian pronounced as /ˈkaːlmaːn ˈkaːdaːr/; born 11 June 1979)[1] is a Romanian water polo player.
Kádár, who comes from the Hungarian minority in Romania,[2] was part of the Romania men's national water polo team that competed at the 2012 Summer Olympics.