The Horten H.IX, RLM designation Ho 229 was a German prototype fighter/bomber designed by Reimar and Walter Horten to be built by Gothaer Waggonfabrik. Developed at a late stage of the Second World War, it was one of the first flying wing aircraft to be powered by jet engines.

Walter Horten and Reimar Horten, sometimes credited as the Horten Brothers, were German aircraft pilots. Walter was a fighter pilot on the Western Front, flying a Bf 109 for Jagdgeschwader 26 in the first six months of World War II; he eventually became the unit's technical officer. Reimar was also trained as a Messerschmitt Bf 109 pilot; however, later in August 1940, he was transferred to the glider pilot school in Braunschweig. He earned his PhD in mathematics from the University of Göttingen, having resumed his studies in 1946 with help from Ludwig Prandtl. The Hortens designed the world's first jet-powered flying wing, the Horten Ho 229.