Creating high-efficiency, multifunctional electrocatalysts for the OER/ORR/HER with exceptional performance and durability is crucial for advancing renewable energy technologies. The rapid advancement in portable water-splitting devices has stimulated significant research interest in rechargeable metal-air batteries and solar cells. However, the scarcity of cost-effective, multifunctional electrocatalysts continues to limit their wide application. Herein, we demonstrate a Ce and Co incorporated, tetraethylene glycol-linked tetraphenyl porphyrin-based covalent organic polymer (Ce-Co-TEGP) exhibiting superior and highly productive multifunctional electrocatalytic activity. The catalyst demonstrated excellent performance toward the OER, ORR, and HER. The O binding sites in tetraethylene glycol moieties aid in incorporating Ce into the system. The optimized Ce-Co-TEGP catalyst exhibited superior catalytic activity with low overpotentials (η10) (280 mV for OER and 170 mV for HER). Additionally, the electrocatalyst shows ORR activity with an onset potential of 0.924 V vs RHE and a limiting current density of -5.9 mA cm-2. The as-synthesized Ce-Co-TEGP catalyst has further exhibited potential as an air-cathode material in rechargeable metal-air batteries. The constructed device exhibited superior open-circuit voltage, increased capacity, and peak power density, along with outstanding discharge-charge performance and extended cycle life.