Edible olive oil is a fundamental component of the Mediterranean diet, valued for its health benefits and economic importance. However, fraudulent practices involving the adulteration of virgin olive oil with lower-quality oils have become widespread, posing risks to both market integrity and consumer health. While conventional detection methods exist, they often require costly equipment or specialized operators. This study presents a novel, cost-effective, and compact optical sensor system designed to identify olive oil adulterations efficiently. The proposed device integrates three optical sensors and light sources operating in the Ultraviolet, Visible, and Infrared frequency bands. It functions in both reflection and transmission modes, providing a spectrogram analysis interpreted through a fuzzy logic system to detect oil adulterations based on reference samples. The system is equipped with wireless connectivity, enabling seamless data transmission to smartphones or computers. The analysis requires only a minimal oil sample and is completed within seconds. Experimental results demonstrate the device’s ability to distinguish adulterated oil samples, highlighting its potential as a practical and accessible solution for ensuring olive oil authenticity.