Iwonicz-Zdrój ([iˈvɔɲit͡ʂ ˈzdruj]) is a spa town in south-eastern Poland, in Subcarpathian Voivodship, in Krosno County.

The Iwonicz forests create a microclimate around the resort, regulating humidity and temperature of the air, protecting it from winds and are a source of ozone.

The resort is situated in the area of the greatest insolation and lowest cloudiness in Poland, which, all-in-all makes it a perfect spot for soothing, refreshing and regenerating the body.

The greatest wealth of Iwonicz land are mineral waters and moor mud, which are natural curative agents.

They are mainly extracted from geological levels so called second and third Ciężkowice sandstone where they occur close to natural gas and crude oil deposits.