Citroën is a French automobile manufacturer, started in 1919 by André Citroën, today part of PSA Peugeot Citroën. Its headquarters are located in Paris, rue Fructidor. Until the late 1980s the company had a reputation for approaching auto design in a unique way.

The story of Citroën begins with the founder of the company himself, André Citroën. After serving in the French army, he set up a gear-making business. In 1919, however, the business started to produce automobiles. In 1928, Citroën introduced the first all-steel body in Europe. The Citroëns sold in large quantities despite the stylistic drawback, but the car's low price was the main selling point and Citroën experienced heavy losses. That encouraged André Citroën to develop the Traction Avant, a car so innovative that to it the competition would have no response.

Citroën unveiled the 2CV at the Paris Salon in 1948. This car become a bestseller. 1955 saw the introduction of the DS, which was the first full usage of Citroën's now legendary hydropneumatic suspension system. This high-pressure hydraulic system would form the basis of many Citroën cars. In 1967 Citroën took control of Maserati, the Italian sportscar maker and launched the sportscar/Grand Tourer SM, which contained a V6 Maserati engine. Huge losses caused by failure of the Maserati tie-up coupled with crippling warranty costs by the unreliable GS and high developement cost of CX led to Peugeot taking over Citroën in 1976. The combined company was known as PSA sold off Maserati to DeTomaso soon after.

Citroën developed a small car for production in Romania known as the Oltcit, which it also sold as the Citroën Axel.

In the 1980s, Citroën models were increasingly Peugeot-based. The BX of 1982 still used the hydropneumatic suspension system, but was powered by Peugeot-derived engines. By the late 1980s, PSA used extensive platform sharing. Citroën's ambitious attitude to engineering and styling was squeezed out in favor of Peugeot conservatism.

In spite of the problems between Peugeot and Citroën, Citroën has continued its tradition for innovation, exemplified by new vehicles such as the C2 and the Xsara Picasso. It has even expanded into new markets, for example in China where the C3 and Xsara are alongside the ZX Fukang and Elysée local models. Proof of this good health, in 2005, for the first time in its history, Citroën is planned to reach a total worldwide production of 1,000,000 cars.