Abstract A sustainable electrochemical protocol has been established for the synthesis of fused polycyclic heteroarenes, which are valuable motifs in medicinal chemistry and materials science. This transformation employs a ruthenium‐catalyzed annulation of quinazolinones with alkynes, driven by the application of electric current. Unlike conventional oxidative annulations that require stoichiometric additives or toxic oxidants, this method relies on electricity as a green oxidant, producing molecular hydrogen as the sole by‐product. The reaction proceeds efficiently under ligand‐free conditions, offering a simple and operationally convenient strategy with excellent atom economy. Importantly, the protocol exhibits broad substrate tolerance, accommodating a wide variety of functional groups on both partners, and consistently delivers the desired fused heteroarenes in synthetically useful yields. Overall, this electrochemical approach provides an environmentally benign and practical alternative to traditional oxidative methodologies, highlighting the potential of electrocatalysis in advancing sustainable heteroarene synthesis.