Phenolic compounds are the most common species found in plants, agro-food matrices, and biological samples. Many conventional and advanced techniques, such as cyclic voltammetry and enzyme-based biosensor, are available to detect phenolics from complex matrices. However, detecting the low concentration of phenolics in complex matrices is challenging. Among them, the electroanalytical method is rapid and allows us to detect phenolics from hazardous organic compounds and biological sources. This method offers high selectivity and low detection limits in determining phenolics contaminants. In this brief, the mechanism of electrochemistry, along with voltammetry, is discussed.