In this study, the effect of Ba doping content on the photocatalytic activity of (Zn1‐xBaxO (ZBO); x=0 to 0.2) thin films is investigated. The efficiency of ZBO photocatalyst for the decolorization of Rhodamine B (RhB) is found to be optimum at x=0.1. The Zn0.9Ba0.1O film exhibits an efficiency of ≈
96% at an irradiation time of 60 min. The high photocatalytic activity of Ba doped ZnO films is attributed to the high efficient generation and separation of photo‐induced charge carriers as evident from photocurrent measurements. Further, the texture and the oxygen vacancies favor the photocatalytic activity as suggested by the x‐ray diffraction (XRD), scanning electron microscope (SEM), x‐ray photoelectron spectroscopy (XPS), Raman spectroscopy and photoluminescence (PL) analysis. Moreover, the reusability test reveals that the photocatalyst performance remains for at least six consecutive cycles without significant change. The higher efficiency and outstanding reusability of Zn0.9Ba0.1O make it a potential candidate for photocatalytic applications.