Hansa-Brandenburg W.34 was a prototype German two-seat, single-engined floatplane, which had been designed by Hansa und Brandenburgische Flugzeugwerke during World War I.
The W.34 was similar in design to the W.33, but was powered by a Basse und Selve BuS.IVa six-cylinder water-cooled engine. The first prototype flew in 1918, shortly before the Armistice. The other two prototypes were operated by the Finnish Navy following the Versailles Treaty and used for coastal defence, being re-engined with Fiat A.12bis engines.