A transverse engine is an engine mounted in a vehicle so that the engine's crankshaft is at a right angle (90°) to the vehicle. Many modern front wheel drive vehicles use a transverse engine mounting design. The majority of rear wheel drive vehicles use a longitudinal engine design, where the engine's crankshaft axis is parallel to the vehicle.

The first car known to use such an arrangement was a 1911 front-wheel drive car. It had a clutch at each end of the engine, driving the front wheels directly. The first successful transverse-engine cars were the two-cylinder DKW "Front" series of cars. These first appeared in 1931. After the World War II, SAAB used the configuration in their first model, the Saab 92, in 1947.

Engines may be placed in two main positions within the motor car:

• Front engine mounted – for front-wheel drive vehicles
• Rear or mid-engine mounted – for rear-wheel drive vehicles