Corrosion represents one of the most pervasive and economically burdensome challenges confronting modern industry, with global annual costs estimated at approximately $2.5 trillion, equivalent to 3-4% of GDP in industrialized nations . Traditional corrosion inhibitors, including chromates, phosphates, and nitrites, have demonstrated high efficacy but pose significant environmental and health concerns due to their inherent toxicity, persistence, and bioaccumulative potential . This comprehensive review systematically examines the emerging paradigm of green corrosion inhibitors derived from renewable, biodegradable sources as sustainable alternatives for metal protection in aggressive environments. Plant extracts, agricultural wastes, biopolymers, amino acids, and naturally occurring organic compounds rich in heteroatoms (N, O, S, P) and conjugated π-systems have demonstrated inhibition efficiencies exceeding 90% through adsorption-driven protective film formation . The review elucidates fundamental adsorption mechanisms—physisorption, chemisorption, and mixed-mode adsorption—governed by molecular structure, surface chemistry, and environmental parameters. Recent innovations in hybrid inhibitor systems, combining green organics with inorganic nanoparticles or metal ions, have achieved synergistic efficiencies of 92-98% through enhanced adsorption strength, barrier integrity, and multifunctionality . Advanced characterization techniques including electrochemical impedance spectroscopy, potentiodynamic polarization, and surface analysis methods are critically evaluated. Computational approaches including density functional theory and molecular dynamics simulations provide mechanistic insights into inhibitor-metal interactions at the molecular level. Key challenges including performance variability, temperature sensitivity, scalability, and standardization are addressed. The review concludes that green corrosion inhibitors represent a viable, sustainable pathway for corrosion management across oil and gas, marine, and infrastructure sectors, with future progress dependent on integrated approaches combining mechanistic understanding, data-driven discovery, and field-relevant validation.