Detroit Diesel Corporation (DDC) is an American diesel engine manufacturer headquartered in Detroit, Michigan. It is a subsidiary of Daimler Truck North America, which is itself a wholly owned subsidiary of the multinational Daimler Truck AG. The company manufactures heavy-duty engines and chassis components for the on-highway and vocational commercial truck markets. Detroit Diesel has built more than 5 million engines since 1938,^[1] more than 1 million of which are still in operation worldwide. Detroit Diesel's product line includes engines, axles, transmissions, and a Virtual Technician service.

Detroit engines, transmissions, and axles are used in several models of truck manufactured by Daimler Truck North America.