A bio‐based vanillin–guaiacol cyanate ester (VGCE) resin was synthesized, and its curing behavior was analyzed using non‐isothermal DSC at heating rates of 2–25°C min −1 . The curing temperature increased with heating rate, and kinetic evaluation yielded activation energies of 69.71 kJ mol −1 (Kissinger) and 73.68 kJ mol −1 (Ozawa), confirming high reactivity and reliability of the model‐free approach. The curing profiles were well described by the Kamal–Sourour autocatalytic model, indicating strong autocatalysis and providing consistent kinetic parameters. The catalytic influence of transition‐metal acetylacetonates (Cu 2 + , Co 2 + , Fe 3 + , V 4 + ) was examined, with Cu(II) at 3 wt.% producing the greatest reduction in polymerization temperature (142°C) and activation energy (50.69 kJ mol −1 ) while maintaining curing enthalpy, demonstrating accelerated network formation. TGA revealed high thermal stability for neat poly(VGCE) (T d i = 319°C, T d 1 = 337°C, char yield = 38.3%), attributed to its aromatic triazine structure. Metal incorporation further increased char yield (up to 45.4%), indicating improved thermo‐oxidative resistance. Crosslink density increased from ϑ ≈ 0.00524 to 0.00554 mol cm − 3 upon Cu catalysis, consistent with higher gel content (96.9% → 98.6%) and enhanced network development. Both neat and Cu‐catalyzed VGCE exhibited excellent hydro‐stability with minimal moisture uptake and maintained desirable dielectric characteristics, with the neat resin showing low‐k behavior (ε′ = 2.94). Overall, the metal‐catalyzed VGCE systems demonstrate strong potential as sustainable, high‐performance thermosetting resins with tunable curing kinetics, thermal stability, and functional properties.