Isuzu Motors Ltd. (いすゞ自動車株式会社, Isuzu Jidōsha Kabushiki-Kaisha^?), (TYO: 7202) is a Japanese car, commercial vehicle and heavy truck manufacturing company, headquartered in Tokyo. In 2005, Isuzu became the world's largest manufacturer of medium to heavy duty trucks.^{[citation needed]} It has assembly and manufacturing plants in the Japanese city of Fujisawa, as well as in the prefectures Tochigi and Hokkaidō. Isuzu is famous for producing commercial vehicles and diesel engines. By 2009, Isuzu had produced over 21 million diesel engines, which can be found in vehicles all over the world. Isuzu diesel engines are used by Renault, Opel and General Motors.

In most of Asia and Africa, Isuzu is mostly known for trucks of all sizes, after Isuzu small automobile sales drastically plummeted and Isuzu had to drop all sales of sedans and compact cars in the late 1990s. In the days when Isuzu did sell passenger cars, they were known for focussing on the diesel-engined niche. In 1983, for instance, long before the explosion in diesel sales, diesels represented 63.4% of their passenger car production. In 2009, Isuzu abandoned the United States consumer market due to lack of sales. Isuzu as a corporation has always been primarily a manufacturer of small to medium compact automobiles and commercial trucks of sizes medium duty and larger, but markets around the world show different needs.