Originally two firms, Hadonghwan Motor Workshop (founded 1954) and Dongbang Motor Co. (founded 1962), which merged to become Hadonghwan Motor Co. in 1963. The company specialized in commercial vehicles, but cooperated with Shinjin in the late 1960s. Civilian versions of the Jeep, which Hadonghwan was manufacturing for the US Army, emerged in 1969 with Shinjin. A technical cooperation deal with AMC was signed in the 1970s. In 1977, the company changed its name to Dong-A, or East Asia. Shinjin had become Geohwa, and had continued making the Jeep, and was taken over by Dong-A in 1984. Ssangyong took over in 1986 and in 1987, it acquired Panther Westwinds of the UK. The company was formally renamed Ssangyong in 1988, the same year the Ssangyong Korando Family SUV was launched. In 1991, it signed a technology partnership with Daimler-Benz AG, with the German company taking an equity stake in 1993. The Ssangyong Chairman luxury car, based on a Mercedes-Benz platform, was launched in 1997, the company branching out from Jeeps and SUVs.
Financial difficulties saw Daewoo take a majority stake in 1998, but this arrangement ended in 2000 when Daewoo itself ran into trouble and it was broken up. The company soldiered on alone, still managing to release new models, and in 2004 SAIC took over. Further difficulties at the time of the global financial crisis saw Ssangyong placed into receivership in 2009. While recovering from this, Mahindra of India acquired Ssangyong in 2011.
Mahindra cut its ties with Ssangyong in 2020 as Ssangyong sunk into debt. It was then acquired by KG Group in 2022, with the Ssangyong name retired in favour of KG. For export, the marque became KGM.