Adam Opel GmbH, commonly known as Opel, is a German automaker. The company was founded in 1863 by Adam Opel. The company originally manufactured sewing machines and later bicycles. It was the leader in both markets at the time of Opel's death in 1895. The first cars were produced in 1899. By 1913, Opel had become the largest car maker in Germany, and in 1924 it installed Germany's first car production line.

In 1929 General Motors, impressed by Opel's modern production facilities, bought 80% of the company, increasing this to 100% in 1931. The company's factories were seized by the Nazi regime in 1940. Passenger car production did not resume until 1947, before which the factories had been badly damaged by Allied bombings, and production assets for the Opel Kadett had been seized by the Soviets as war reparations (this Kadett forming the basis for the Soviet car Moskvitch 400/420).

GM regained control of Opel in 1948. By 1972, Opel was once again Germany's largest car maker. Many cars sold by General Motors worldwide are Opel designs.

On 10th September 2009, it was announced that Magna, a Canadian automobile parts manufacturer, and Sberbank, a Russian bank, will buy a majority stake (55%) in the GM’s European Opel/Vauxhall operations. GM will own 35% of Opel; while Opel employees will own 10%. The agreement will keep Opel/Vauxhall a fully integrated part of GM’s global product development organization, allowing all parties to benefit from the exchange of technology and engineering resources.

The lightning bolt on the Opel badging is a reference to the famous Opel Blitz truck (the German word 'Blitz' means lightning or flash). The logo was originally a Zeppelin, which became more stylized, and as the Zeppelin became less popular as a form of transport, the logo was changed. There is also a noticeable similarity between the winged Zeppelin and the lightning logo.