Iwaniska [ivaˈniska] is a village in Opatów County, Świętokrzyskie Voivodeship, in south-central Poland. It is the seat of the gmina (administrative district) called Gmina Iwaniska. It lies approximately 14 kilometres (9 mi) south-west of Opatów and 50 km (31 mi) east of the regional capital Kielce.