The Nissan Diesel UA (kana:日産ディーゼル・UA) was a full-size single-decker bus produced by the Japanese manufacturer Nissan Diesel for 32 years of production from 1973 until 2005. It can be built as either a bus chassis or an integral bus. Competitors of the UA include the Isuzu Cubic, Mitsubishi Fuso Aero Star and the Hino Blue Ribbon.