An ultraviolet disinfection (UV) system for appliances including at least one UV light-ready appliance having at least one portal in the appliance for receiving UV light input from at least one light source, which is removably connected to the at least one UV light-ready appliance via a connector at the portal, and positioned to provide a focused, controllable UV light output that has at least one UV dose zone for providing effective sterilization of microorganisms and disinfection within an interior of the appliance. Also, an ultraviolet disinfection (UV) system for appliances, the system comprising at least one light source positioned within a housing that is external to at least one appliance and capable of being connected thereto via at least one connector and connected to a power source for producing a UV light output from the housing; this system includes at least one source optical component positioned between the at least one light source and the UV light output from the housing, thereby producing a focused, controllable UV light output that has at least one UV dose zone for providing effective sterilization of microorganisms within the at least one appliance. A method for UV disinfection of the interior of appliances is also included in the present invention.