In this work, bio-based hybrid coating using Ag-TiO2 (AgT) sol and cardanol epoxy (CE) was developed, coated over mild steel (MS) substrates and studied for its corrosion resistant efficiency. Initially, the AgT sol was prepared and successively surface-functionalized using 3-glycidoxypropyl-trimethoxysilane (GPTMS) using a sol–gel approach to achieve compatible with the CE matrix. The physico-chemical and antimicrobial properties of neat CE and CE composites with different wt% of GAgT (GAgTx/CE) were studied using various analytical techniques and microbial assays, respectively. Further, CE and the GAgTx/CE composites were coated over MS, and their corrosion resistant behavior against microbial co-culture medium (MCM) (i.e. nutrient medium amended with 3% w/v NaCl and inoculated with both Micrococcus luteus and Pseudomonas aeruginosa) was evaluated by electrochemical techniques at different periods. The results suggested that the presence of GAgT along with CE matrix provided enhanced hydrophobicity with low surface free energy, which consequently lowered the interfacial interactions between the microbes and MS substrates. The optimum loading of GAgT in CE was 3 wt.%, showing enhanced resistance as high as 1097 Ω even after 21 days in MCM and thus renders durable corrosion resistance. In addition, the zone of microbial inhibition and water contact angle (WCA, θW = 94) of 3% GAgT/CE was comparatively higher than the other coatings. Our results suggest that further different hybrid coatings using cardanol epoxy can be developed in order to exploit the full potential of bio-material with different substrates as desired for sustainable coatings in industrial applications.