<p>This paper presents a voltammetric method for the electrochemical determination of chloramphenicol (CAP) using a carbon paste electrode modified with graphitic carbon nitride (<i>g</i>-C₃N₄/CPE). CAP is a broad-spectrum antibiotic that has often been identified as a contaminant in environmental and food samples. The modifier (<i>g</i>-C₃N₄) was synthesized via the thermal polycondensation of melamine; a temperature of 650&#xa0;°C was determined to be optimum as it enhanced the analytical signal and altered the reduction potential of CAP. Electrochemical characterization was performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square-wave voltammetry (SWV). Under optimal conditions, the sensor demonstrated a linear dynamic response ranging from 1.00 × 10⁻⁷ to 4.18 × 10⁻⁶&#xa0;mol L⁻¹ with a detection limit of 7.91 × 10⁻⁸&#xa0;mol L⁻¹ in Britton‒Robinson buffer (0.04&#xa0;mol L⁻¹, pH = 7.00). This approach resulted in remarkable precision, with relative standard deviations (RSDs) of 2.0% for repeatability and 8.0% for reproducibility. The proposed method was effectively used for CAP quantification in milk and water samples, thereby underscoring its dependability and potential for environmental and food safety surveillance.</p>