Johannes Winkler (May 29 1897 - December 27 1947) was a German rocket pioneer who launched the first liquid-fuelled rocket in Europe, the HW-I on March 14, 1931.

Winkler was born in Carlsruhe. In 1915 he joined the German army and was wounded in action the following year, leading to a lengthy hospitalisation. After his recovery, he studied as a machinist at the Danzig technical college and found a job at Junkers.

With a growing fascination for aerospace, on July 5 1927, he founded the Verein für Raumschiffahrt (VfR - "Spaceflight Society"), an amateur rocketry group, and became its first president. This club would eventually attract over 500 members, including many who would become influential in shaping humanity's journey into space. He also acted as the society's first president and journal editor.

The flight of his HW-I rocket near Dessau in 1931 was followed by the design of a more powerful rocket, the HW-II eighteen months later. This was launched in a public demonstration, which included invited officials from the Königsberg council. Unfortunately, the rocket exploded within seconds of ignition because of a faulty fuel valve.

Winkler designed a number of other rockets and RATO units for Junkers and then a government aviation research institute, but none left the drawing board. He died not long after the end of World War II at Braunschweig-Querum .