UD Trucks Corporation (UDトラックス株式会社, UD Torakkusu Kabushikigaisha, Utopia Diesel) is a Japanese company whose principal business is the manufacture and sales of light, medium and heavy duty diesel trucks, buses, bus chassis and special-purpose vehicles. The company is owned 100% by the Volvo Group since 2007. Formerly known as Nissan Diesel, the company changed its name to UD Trucks (Utopia Diesel Trucks) on February 1, 2010. Already before the name change, the UD name was prominently displayed to separate the identity from that of their former ownerNissan Motors.
The UD name was originally used for the company's Uniflow Diesel Engine (known as Two-stroke Engine), developed in 1955, but is now marketed as meaning "Ultimate Dependability".