This subseries documents Citroën, which was built by André Citroën, Ingénieir-Constructeur of Paris, France (1919-1924); Société Anonyme André Citroën of Paris, France (1924-1968); Automobiles Citroën, Citroën S.A. of Paris, France (1968-1976); and PSA Peugeot Citroën of Paris, France (1976-1979) and Neuilly-sur-Seine, France (1979-Present).

Founded by André Citroën in 1914, Citroën is noted for innovation and built a number of memorable and technologically advanced mass-produced cars over the course of its history, including the Traction Avant, 2CV, and DS 19. The make also has a complicated history. In 1934, Citroën filed for bankruptcy and was taken over by Michelin, who ran the company for many years. The firm experienced a period of rapid growth during the late 1960s, which was prompted by its acquisitions of Panhard in 1963 and Maserati in 1968.

Citroën suffered heavy financial losses during the early 1970s, largely brought on by the 1973 Energy Crisis and the failure of the Comotor rotary engined car. At the instigation of the French government, the firm merged with Peugeot in 1974. As part of its restructuring, Maserati was sold off to De Tomaso in 1975. Citroën is presently a subsidiary of PSA Peugeot Citroën. See also Maserati, Panhard, and Peugeot (France).