Graphene oxide (GO) has emerged as a transformative nanomaterial for advanced corrosion protection coatings, leveraging its unique two-dimensional lamellar architecture and abundant surface functional groups to provide both passive barrier properties and active inhibition capabilities. This comprehensive review systematically examines the multifaceted role of GO in multifunctional coatings, focusing on how surface functionalization and 2D lamellar structure synergistically enhance barrier properties and active corrosion protection. The physical barrier mechanism of GO arises from its high aspect ratio and impermeable nature, creating tortuous diffusion paths for corrosive species, with a 0.03 wt% addition to geopolymer coatings achieving high impedance modulus and ultra-low corrosion current density through a triple synergistic protection system integrating physical barrier, chemical adsorption, and structural reinforcement . Surface functionalization strategies—including carboxylation (-COOH), hydroxylation (-OH), amination (-NH₂), and dopamine/nano-TiO₂ co-modification—critically influence coating performance by improving dispersion, enhancing interfacial compatibility, and introducing active inhibition functionality . Dopamine and nano-TiO₂ co-modified GO demonstrates superior corrosion resistance through synergistic effects: polydopamine enhances dispersion while TiO₂ provides passivation film effects, covering CO groups on GO surface . Carboxylated GO (CGO) composites outperform hydroxylated and aminated counterparts, with CGO-15 coating achieving two orders of magnitude higher impedance modulus than pure resin and over 90% inhibition of sulfate-reducing bacteria through ROS-mediated oxidative stress . The interlayer entanglement toughening strategy improves GO paper delamination strength by 268%, approaching benchmark natural nacres . This review concludes that integrated design combining molecular functionalization, 2D architecture optimization, and multi-component hybridization offers transformative potential for durable, high-performance protective coatings.