A two-cylinder two-stroke engine, mounted transversely in a 1955 Saab 92B.

A transverse engine is an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle. This is also sometimes called an east-west engine. Most modern front wheel drive vehicles use this engine orientation, while most rear wheel drive vehicles use a front-to-back longitudinal arrangement.

The first car to use such an arrangement was the two-cylinder DKW "Front" series of cars, which first appeared in 1931. After the Second World War, SAAB used the configuration in their first model, the Saab 92, in 1947. The arrangement was also used for the Borgward Hansa and in a few other German cars. However, it was with Alec Issigonis's Morris Mini that the design gained acclaim, in 1959.

This design reached its ultimate extent starting with Dante Giacosa's elaboration of it for Fiat. He connected the engine to its gearbox by a shaft and set the differential off-center so that it could be connected to the gearbox more easily. Now most cars built throughout the world use this arrangement.

The Lamborghini Miura used a transverse, mid-mounted 4.0 litre V12, a configuration that was unheard of in 1965, although now more common.