Carbon dioxide (captured from the atmosphere or obtained by other routes) constitutes a useful and widely available building block for producing numerous valuable chemicals and fuels. Electrochemical methods for carbon dioxide reduction offer advantages in terms of scalability, the prospect of coupling directly to renewable power sources and the ability to reduce carbon dioxide without the co-production of harmful by-products. Of the various possible products of carbon dioxide electroreduction, oxalate/oxalic acid is an especially attractive target because of its wide use in many chemical and pharmaceutical processes. Herein, we report the results of a study on carbon dioxide electroreduction to oxalate/oxalic acid in a propylene carbonate solvent system, catalysed by the addition of benzonitrile. Our results show that the use of benzonitrile as a homogeneous electrocatalyst improves the faradaic and reaction yields of oxalate/oxalic acid production, as well as the area-normalised rate of formation of oxalate/oxalic acid, giving a new record rate of formation of 1.65 ± 0.35 mM cm⁻² h⁻¹ (averaged over 1 h) at a voltage of –2.7 V vs. SCE (–2.46 V vs. SHE). Such metrics in turn suggest that the electrochemical reduction of carbon dioxide to C₂₊ products via oxalate could be a promising avenue for further development for the sustainable production of key chemical feedstocks.