Although, Low-pressure (LP) mercury lamps that emit wavelengths of around 254 nm have been widely applied as ultraviolet (UV) light devices for decontamination of microorganisms, they have raised environmental concerns due to their mercury content. Therefore, UV-LED lamps have high potential for practical use as a replacement for LP mercury lamps. In this study, we evaluated the efficacy of 265-nm UV irradiation in comparison to 254-nm and 280-nm UV irradiation for inactivating infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Irradiation from a 265-nm deep UV light-emitting diode (DUV-LED) lamp efficiently inactivated SARS-CoV-2 at a similar level as a 254-nm UV cold cathode lamp, and at a higher level than a 280-nm DUV-LED lamp.