The non-sustainability of conventional benzoxazine and epoxy resins is highly concerning and the development of suitable bio-alternative materials is very much warranted without compromising the end properties. Considering the preceding fact, the present study reports the synthesis of bio-based tetrafunctional benzoxazine (T-f) and epoxy (T-e) blends to attain a highly thermally stable hybrid polymer system. Upon blending T-e with T-f, the curing temperature is reduced from 225°C to 175°C. Also, the prepared epoxy resin shows a curing temperature of 230°C. The blend shows excellent thermal stability with a char yield of 59%. Also, two ceramic-based fillers were prepared and reinforced into the blend. The thermal stability of the composites was increased remarkably with a char yield up to 70%. Also, the dielectric constant of the composites was increased to 6.54 at 10 MHz. The ceramic composites show superhydrophobic behavior with a water contact angle reaching up to 161°.