In the present work, amine‐functionalized palm flower carbon (f‐PFC)‐reinforced 9, 10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐urea diamine‐based cardanol benzoxazine‐epoxy hybrid (DUDCBz‐EP) composites have been developed and characterized. Differential scanning calorimeter analysis indicate that the amine‐functionalized palm flower carbon‐reinforced cardanol‐benzoxazine/epoxy (f‐PFC/DUDCBz‐EP) hybrid composites possess the higher values of glass‐transition temperature (Tg) than that of hybrid matrix (DUDCBz‐EP). Results from TGA infer that the PFC reinforcement significantly improves thermal stability and char yield according to the percentage weight. Morphological studies ascertain the amorphous structure and uniform as well as homogeneous dispersion of PFC reinforcement in the hybrid matrix. Contact angle measurements indicate that both the hybrid matrix and composites developed in the present work possess hydrophobic behavior. Data obtained from corrosion studies infer that the hybrid matrix as well as hybrid composites exhibit significant corrosion‐resistant behavior toward the surface of the steel specimen due to inherent characteristics of both benzoxazine and epoxy matrix, in addition to amine‐functionalized PFC. The results obtained from different studies, it is suggested that these hybrid matrix possess significantly improved properties and can be exploited for high‐performance cost competitive coatings for different industrial applications including protection of steel surfaces from corrosion. POLYM. ENG. SCI., 60:732–739, 2020. © 2020 Society of Plastics Engineers