Heterogeneous photocatalysis is an effective and gifted waste water treatment technology for the removal of textile effluents. Among the effective photocatalytic treatment, Hybrid semiconductor photocatalysts have been extensively applied and received greater attention in the last few decades. This effective statement has a predominate key for choosing hybrid nanocomposite photocatalysis. In this study, Mn doped CdS/ZnO nanocomposites synthesized by co-precipitation method and its photocatalytic activity tested using methylene blue under solar light irradiation. The as prepared hybrid nanocomposites is characterized by using different physicochemical techniques including X-ray diffraction, FESEM, EDX, TEM, UV-vis DRS and PL analysis. The photocatalytic degradation results have revealed that the Mn doped CdS/ZnO nanocomposites exhibits admirable activity toward the photocatalytic degradation of the MB. The fitted kinetic plots were showed a pseudo-first-order reaction model and the appropriate rate constants were found to be 0.0068 min− 1, 0.00846 min− 1, and 0.0188 min− 1, for ZnO, 25% CdS/ZnO, and 0.8 mol% Mn doped CdS/ZnO nanocomposites, respectively. The maximum photocatalytic activity was achieved by 0.8 mol% Mn doped CdS/ZnO nanocomposites with a 95% degradation efficiency of MB. Hydroxyl and superoxide radicals were having a vital role in the degradation of MB, confirmed by scavenging experiments. In addition, the recycling tests display that the Mn doped CdS/ZnO nanocomposites shows good stability and long durability. The enhanced photodegradation activity of Mn doped CdS/ZnO nanocomposites indicates the potential of the nanocomposite for the treatment of organic pollutants from the textile wastewater.