An environmentally friendly chemical method was used to reduce the graphene oxide (GO) and subsequently, noncovalent functionalization of the GO with dopamine hydrochloride was carried out via self-polymerization reaction under a weak alkaline condition. The as-prepared nanocomposite was donated as PDA-rGO and later on, flame-retardant coatings were developed into the flexible polyurethane foams (FPUFs) surfaces using polyacrylic acid, and polyethyleneimine along with PDA-rGO via layer-by-layer assembly. The growth process of the deposited coatings was tailored by altering the pH and concentration of the PDA-rGO suspension. Cone calorimeter test results indicated that PDA-rGO-based coating with three tri-layer deposition effectively reduced the peak heat release rate by 49.3%, the total smoke release by 33.1%, and the peak of release for the production of CO by 46.2% compared to the neat FPUF, which could be attributed to the physical barrier effect of rGO sheets and the free-radical scavenging property of polydopamine.