Many cars sold by General Motors worldwide are Opel designs, including such models as the Corsa, Astra, Vectra and Omega. Opel models are also sold under other GM brand names, such as Vauxhall in the UK, Holden in Australasia, Saturn in North America, and Chevrolet in Latin America. Its' Zafira people carrier was sold in Japan badged as a Subaru Traviq, while the Omega was briefly sold in the US as the Cadillac Catera. Other models sold in the US, but slightly modified, include the Saturn L-Series, Chevrolet Malibu and Cobalt. The majority of future Saturn models are expected to be either identical, like the Saturn Astra and Sky, or closely based, like the Aura and 2008 Saturn Vue, to European Opels. The Pontiac LeMans (1989-1994), which was the first car produced by Daewoo in South Korea for export to North America, were based on the Opel Kadett E (now Astra).

Opels appeared under their own name in the USA from 1958 to 1975, when they were sold through Buick dealers as captive imports. The best-selling Opel models in the US were the 1964-1972 Opel Kadett, the 1971-1975 Opel Manta, and the now-classic 1968-1973 Opel GT. (The name "Opel" was also applied from 1976 to 1980 on vehicles manufactured by Isuzu (similar to the "Isuzu I-mark"), but mechanically those were entirely different cars).

Opel was long General Motors' strongest marque in Japan, with sales peaking at 38,000 in 1996. However, the brand has diminished in the decade since, and will reportedly be withdrawn by the end of 2006 with just 1,800 sales there in 2005.

Opel in Europe

Opel is the main GM brand name in Europe except in the UK, where GM's other European subsidiary, Vauxhall Motors, still uses its own "Vauxhall" brand name. Vauxhall's models were completely different designs from those of Opel, until the 1970s. The Opel name largely disappeared from the UK in 1981 after Vauxhall and Opel dealerships were merged, with only the Manta and the Monza (the coupe version of the Senator) being sold as Opels, until they were discontinued in 1988 and 1987 respectively.

Vauxhall began adopting Opel's names for its models, with the exception of 'Kadett' which was replaced by Astra, already used by Vauxhall, in 1991. In other right hand drive markets in Europe like Ireland, Cyprus and Malta, the main GM brand name is now Opel, and for many years, Opel's Ireland brand sponsored the Republic's football team, using the slogan Ireland's Number One Supporter. However, many Vauxhall cars, imported second hand from the UK, are still sold in Ireland as a parallel import.

Some have suggested that the Vauxhall name should be dropped in the UK in favour of Opel, thereby harmonising GM's marketing strategy across Europe. However, Vauxhall has rejected this, on the grounds that its brand is well known, and fleet buyers, who are its main customer base, insisted that Opel models be rebadged as Vauxhalls. Opel will also provide design and engineering to the American Saturn marque, similar to the Vauxhall situation in the UK.

The company headquarters are located in Rüsselsheim, and it has plants in Bochum and Eisenach and Kaiserslautern as well as in Belgium, Spain, Poland and Hungary. Opel cars are also made in Vauxhall's Ellesmere Port plant in the United Kingdom.

In October 2004 employees went on strike for six days due to the threat of 12,000 job losses. The threat was due to the unprofitable European markets because of low customer demand. The strike had a major impact on production.

In 2005, the new Opel Astra Diesel Hybrid appeared.

In 2006, the Azambuja, Portugal factory shut down and the production of the Opel Combo transferred to Zaragoza, Spain. The move prompted a national boycott movement and caused the Portuguese Government to sue General Motors.