<p>The mixed discharges of dye-containing effluents with antibiotic-laden wastewater results in the coexistence of dye and antibiotic pollutants in wastewater. Such diverse pollutants pose a significant environmental risk due to their toxicity, persistence and resistance to traditional treatment techniques. Improper wastewater treatment and the reuse of treated water for irrigation further contribute to the co-occurrence of such pollutants in natural water bodies. Therefore, it is necessary to develop an effective, reusable, solar light-active and environmentally sustainable photocatalyst that can break down both dye and antibiotic contaminants. In this context, graphene oxide-modified manganese-nickel ferrite (GO/MNF) nanocomposites were synthesized via co-precipitation route and evaluated for the photocatalytic degradation of both cresol red (CR) dye and tetracycline hydrochloride (TCH) antibiotic under solar light irradiation. Systematic variation of graphene oxide loading revealed that GO-40/MNF exhibited optimal photocatalytic performance, achieving degradation efficiencies of 93.8% for CR within 90&#xa0;min and 91% for TCH within 120&#xa0;min. Structural and morphological analyses confirmed the successful incorporation of GO, leading to enhanced surface area, improved light absorption and suppressed charge-carrier recombination. Radical scavenging experiments identified photogenerated holes as the dominant reactive species, with hydroxyl and superoxide radicals contributing to pollutant degradation. The photocatalyst demonstrated moderate stability and acceptable reusability over five consecutive cycles. Phytotoxicity assessments using fenugreek seeds confirmed significant detoxification of treated solutions, indicating environmental safety. This study demonstrates GO/MNF as a promising photocatalyst for the removal of diverse organic pollutants from aquatic system due to the synergistic interface formed between GO and the mixed ferrite nanoparticles.</p>