Rice starch (RS-)based nano/mesoporous carbon (RSNMC) was prepared via a hard-templating route using cheap rice starch as a carbon source. XRD and TEM characterization indicated the formation of organized nanoporous RSNMC. Nitrogen absorption-desorption studies revealed a high surface area of up to 488 m²∙g-1, uniform pore size of 3.92 nm, and pore volume of 1.14 cm³∙g-1. A RSNMC-modified glassy carbon (GC) electrode was employed for the determination of ascorbic acid (AA) and exhibited a linear response in the concentration range of 0.005-6.0 mM with a detection limit of 0.003 mM. These results demonstrate that RSNMC has potential as an advanced and cheap electrode material for electrochemical sensing and other electrocatalytic applications.