The design of superhydrophobic, anti-corrosion, anti-icing and self-cleanable coatings has received increasing interest in the field of transportation, energy and infrastructure. In this context, a new bio-based cardanol-phthalein cored bisphenol (CP) as a precursor for coating materials was synthesized using cardanol and phthalic anhydride under appropriate experimental conditions. The two different aliphatic amines [(Jeffamine-D230 (jef) and 4,7,10-Trioxa-1,13-tridecanediamine (ttd)] were used for the preparation of CP based benzoxazines (CP-Bz) to achieve multifunctional surface protection with superhydrophobic, anti-icing and self-cleaning characteristics. Structural confirmation was performed using FTIR, and 1H NMR analyses. The curing behaviour of monomers were analysed using DSC, and among the benzoxazine monomers synthesized, CP-ttd possesses the lowest curing temperature of 180°C. The synthesized cardanol-phthalein benzoxazine (CP-Bz) monomers were polymerized through thermal curing to form cross-linked polybenzoxazine networks. The poly(CP-ttd) exhibited an excellent thermal stability with a T5% of 385°C, Tmax of 515°C and a char yield of 26% as determined by thermo-gravimetric analysis (TGA). The water contact angle measurements infer that the polybenzoxazines approaches to the superhydrophobic surface with the values ranged between 136° and 150° ± 2°. Electrochemical impedance spectroscopy (EIS) and potentio-dynamic polarization tests indicated better corrosion resistance, with an impedance modulus of 1.30 x 107 Ω cm2 and a corrosion density (Icorr) of 11 μA cm−2 representing a three-order of magnitude improvement compared to that of bare steel substrate. Anti-icing study of the CP polybenzoxazines coatings showed delayed ice formation with a freezing time of 600 s compared to that of cardanol polybenzoxazines coatings. Also, the efficient self-cleaning nature of the CP based polybenzoxazine coatings was achieved and reported. The poly(CP-ttd) coated on glass substrate exhibited the superhydrophobic water contact angle value of 150°. These findings shows that cardanol-phthalein cored benzoxazine coatings can serve as high-performance alternatives for advanced protective and anti-contaminant applications in aerospace, marine, and energy sectors.