Food safety is a major concern in food production. Many chemical, physical, and thermal methods currently exist to reduce or eliminate pathogenic and spoilage microorganisms commonly associated with food. However, some of these methods may not be effective enough and can lead to unsafe food, quality deterioration, or undesirable residues. Thus, some alternative food processing methods are being developed and evaluated for the purpose of ensuring microbial food safety for various food applications. Microbial decontamination of food by light-based technologies, including ultraviolet (UV) light, pulsed UV (PUV) light, and UV light-emitting diodes (UV-LED), are alternative microbial intervention methods used for food decontamination. This chapter provides a fundamental understanding of these light-based technologies and explains the microbial inactivation mechanisms. A review of literature includes the effectiveness of UV light-based technologies for food decontamination and addresses the critical factors affecting the microbial decontamination of the technologies. Limitations, regulation and future trends are also discussed.