The Nissan Diesel C-series (Japanese: 日産ディーゼル・Cシリーズ) was a heavy-duty commercial vehicle that was produced by the Japanese manufacturer Nissan Diesel (now UD Trucks) and sold in two generations between 1971 and 1990 (although production continued into the 1990s for certain markets).

The C-series was replaced by the Nissan Diesel Big Thumb in 1990.

The first generation Nissan Diesel C-series trucks were built from 1971 until 1979.

This was also when the name was changed to Resona in Japan (short for "resonate"),[2] although Nissan Diesel reverted to using the C-series name in 1986.

"[3] The New Zealand importer also developed their own twin-steer 8 x 4 version (CGA340) with the second axle set farther forward than on Japanese-market trucks.