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.

• U/UA20/30 (1973)
• U35 (1975)
• K-U/UA31/36 (1980)
• P-U/UA32 (1984)
• P-U/UA33/50 (1988)

• 
  U U20Hkai
• 
  UA K-UA31L
• 
  U P-U32L

One-step and Two-step

• U-UA440/510/520 (1990)
• KC-UA460/521 (1995)
  • KC-UA460HANkai (ERIP Hybrid, 1995)
• NE-UA4E0 (CNG, 1996)
• KL-UA452 (2000)

• 
  U-UA440NSN
• 
  NE-UA4E0HSN (CNG)
• 
  KL-UA452PAN
• 
  U-UA440LAN

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.

• F type
  • UA460KAM (1997)
  • KC-UA460KAM (1998)
  • KL-UA272KAM (2000)
• N type
  • KL-UA272KAM (2003)
• G type
  • KC-UA460 (2000)
  • KL-UA452 (2000)

• 
  Non-step F type KL-UA272KAM
• 
  Non-step G type KL-UA452KAN
• 
  Non-step G type KL-UA452KAN

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

• Nissan Diesel Space Runner A
• Nissan Diesel Space Runner RA
• Nissan Diesel Space Runner RM