Alexander Martin Lippisch (2 November 1894 – 11 February 1976) was a German aeronautical engineer, a pioneer of aerodynamics who made important contributions to the understanding of tailless aircraft, delta wings and the ground effect, and also worked in the U.S. Within the Opel-RAK program, he was the designer of the world's first rocket-powered glider.

He developed and conceptualized delta wing designs which functioned practically in supersonic delta wing fighter aircraft as well as in hang gliders. People he worked with continued the development of the delta wing and supersonic flight concepts over the 20th century. His most famous designs are the Messerschmitt Me 163 rocket-powered interceptor and the Dornier Aerodyne.

Lippisch was born in Munich, Kingdom of Bavaria. He later recalled that his interest in aviation began with a demonstration conducted by Orville Wright over Tempelhof Field in Berlin in September 1909. Nonetheless, he planned to follow his father's footsteps into art school, until the outbreak of World War I intervened. During his service with the German Army, between 1915 and 1918, Lippisch had the chance to fly being an aerial photographer and mapper.

Following the war, Lippisch worked with the Zeppelin Company, and it was at this time that he first became interested in tailless aircraft. In 1921, his first design to be built, by his friend Gottlob Espenlaub, was the Espenlaub E-2 glider. This was the beginning of a research programme that would result in some fifty designs throughout the 1920s and 1930s. Lippisch's growing reputation saw him appointed in 1925 to director of the Rhön-Rossitten Gesellschaft (RRG), a glider organisation including research groups and construction facilities.

Lippisch also designed conventional gliders at this time, including the Wien of 1927 and its successor the Fafnir of 1930. In 1928, partaking in the Opel-RAK program by Fritz von Opel and Max Valier, Lippisch's tail-first Ente (Duck) was equipped with powder rockets by Friedrich Wilhelm Sander's company and became the first aircraft to fly under rocket power. From 1927, he resumed his tailless work, leading to a series of designs named Storch I – Storch IX (Stork I-IX), mostly gliders. These designs attracted little interest from the government and private industry.

Experience with the Storch series led Lippisch to develop what he called his Delta designs. Like the Storch series, these were mostly tailless aircraft. They included the earliest successful delta wing designs. In 1931 the Delta I glider became the first to fly. It was followed by the Delta II and III.

The Delta IV design was powered, and built in two variants as the Fieseler F3 Wespe. Lippisch subsequently designated these the Delta IVa and b, with the c being built as the DFS 39. The development of this led directly to the Messerschmitt Me 163 Komet (see next section), which Lippisch has also referred to as the Delta IVd.

The Delta V, built as the DFS 40 was a blended wing body design for comparison with the DFS 39.