The U-3 class was a class of two submarines or U-boats built for and operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine). The U-3-class boats were designed and built by Germaniawerft of Kiel, Germany. The class was a part of the Austro-Hungarian Navy's efforts to competitively evaluate three foreign submarine designs.