The commercialization of fruit is compromised by their rapid maturation and postharvest decay. Ultraviolet (UV) light—based technologies are both non-thermal and mild thermal physical preservation techniques that have been successfully used to reduce pathogenic and spoilage microorganisms on the surface of the fruit and in transparent juices, extending their shelf life. But besides its germicidal properties (majorly attributed to the UV-C region of the UV spectrum), UV light has numerous modes of action on living cells, entailing biological (beneficial or negative) effects in the fruit matrix, which depend, among others, on the type of UV illumination source, the wavelength(s) and the doses applied, and the storage temperature. Exposure of fruit to UV hormetic doses during postharvest processing can stimulate a defense response in plant tissues (which could lead to the elicitation of secondary metabolites with antimicrobial and antioxidant properties), delay ripening and senescence, and induce fruit resistance to heterologous stresses. Another not very studied UV light application in fruit is the reduction of toxic organic compounds’ levels (i.e. mycotoxins). Recent developments in UV light-emitting diodes (UV LED) lamps, and advances in knowledge on the microbial response, the physiological effects in fruit, and the combination of UV light with other antimicrobial factors for increasing the germicidal effectiveness, may facilitate industry-wide adoption of these lighting technologies.