The facile sol‐gel and hydrothermal method have been used to prepare the ternary heterojunction of rGO supported NiFe2O4/g‐C3N4 nanocomposite. The structural, morphological, optical, magnetic, and charge transport properties of the prepared nanoparticles were analyzed by various analytical methods. The supportive rGO helps to harvest the more amount of visible light and helps to electron transformation was confirmed by UV‐vis‐DRS and PL spectroscopy studies. The rGO acts as an electron transport supporting layer for enhancement of radical production for effective dye degradation reaction under LED and sunlight irradiation. In particular, 10GO/NFO/g‐CN ternary nanocomposite exhibits the highest photo‐Fenton degradation when compared to other photocatalysts. They produced a large amount of OH• radicals that were beneficial for the photocatalytic process. The possible reaction mechanism and the active species for the dye degradation process were investigated by elemental trapping experiment and TA test. The recycling process proves the stability of the prepared photocatalyst. Hence, the reported ternary heterojunction could be a superior candidate for environmental remediation applications.