During World War I, Porsche designed and developed aircraft engines and motorized artillery for Austro-Daimler, contributing to the war effort for the Austro-Hungarian Empire.

Even before World War II officially began, Porsche was involved in the design of tanks and other military vehicles for the German military. This was a period of military build-up, and Porsche's expertise was sought after.

Based on the Volkswagen Beetle's design, Porsche's firm developed the Kübelwagen (a military utility vehicle) and the Schwimmwagen (an amphibious vehicle) for the German Wehrmacht. These vehicles proved highly effective in various terrains.

Porsche was involved in the design of the Panzerkampfwagen VIII Maus, a super-heavy tank. While only prototypes were built, it represents a significant (though ultimately impractical) example of his wartime engineering work.

Porsche also contributed to the development of the Tiger tank through the VK 4501 (P) prototype. Though his design wasn't ultimately selected, it demonstrated his involvement in developing heavy armored vehicles.