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.

Competitors of the UA include the Isuzu Cubic, Mitsubishi Fuso Aero Star and the Hino Blue Ribbon.

One-step and Two-step Non-step The Nissan Diesel UA Non-step is considered as one of the low floor variants, sometimes in other parts of Japan, it is known as a low entry variant.

Other low floor models include the Space Runner RA and the Space Runner RM.

Other Nissan Diesel low-floor (non-step) bus models sold in Japan: