The present work investigates structural, optical and hydrophobic properties of zirconium oxynitride films deposited on glass substrates by reactive RF magnetron sputtering. Influence of the oxygen partial pressure in N₂ + Ar and N₂ + He mixtures on the formation of zirconium oxyntride films was examined. The structures of the films were analyzed by X-ray diffraction, FE-SEM/EDS, AFM and contact angle measuring system. Structural transformation from Zr₂ON₂ to well oriented m-ZrO₂ is observed as oxygen partial pressure is increased beyond 4.0% when deposited in helium due to penning ionization. The thicknesses of the films were examined by surface profilometer and closely matched with the calculated one from transmission data. The deposited films are hydrophobic and the contact angle decreases with surface roughness. The optical properties of the films were measured by UV–Vis–NIR spectrophotometer and transmittance of ∼99% in the visible region of the spectrum was achieved. The band gap increases with increase in oxygen partial pressure and is higher in N₂ + He mixture than in N₂ + Ar mixture.