Ultraviolet (UV) light is the range of electromagnetic radiation immediately more energetic than the visible range. UVC light has been found useful for disinfection in a variety of areas, including but not limited to air disinfection, water (and wastewater) treatment, laboratory disinfection (especially inside biosecurity cabinets), food and beverage preservation, and medical applications. UVC light has limitations as a disinfectant, mainly due to the need for adequate photon flux over the surface or atmosphere of interest. A common source of UVC in commercial applications is the standard “germicidal” lamp. The application in livestock production is a recent development and may be of increasingly higher interest for farmers to implement to defend the farms from infectious diseases such as African swine fever (ASF). However, the knowledge gap exists for producers and veterinarians in terms of the physics/mechanisms of UVC, the doses required to inactivate swine pathogens, and practical conditions under which UVC can operate effectively and practically on swine farms. To address this issue, this paper incorporates the overview of UVC light that is applicable for germicidal purposes, mechanisms of inactivation, UVC dose calculation, measurement of UVC, factors affecting UVC germicidal effectiveness, UVC light system components, and UVC light bulb selection to better inform the operator to effectively apply UV technologies in animal production.