Originally, Hummers were built in South Bend, Indiana, by AM General Corporation, which was the government vehicle division of American Motors. AM General had planned a civilian version of the large vehicle as long ago as the late 1980s. Publicity for such a vehicle began in 1990 when two matching white Hummers were driven from London to Beijing over the less-than-perfect roads of the then Soviet Union. Built to go off-road, they made the trip with no problems, and their journey was broadcast on ESPN. The next year, the Hummer's military version, the HMMWV (High Mobility Multipurpose Wheeled Vehicle, or Hum-Vee) garnered even more attention because of its use during Operation Desert Storm.

The first civilian version of the Hum-Vee was made available to the public in 1995 under the name Hummer, allegedly because Arnold Schwarzenegger asked them to. (The rumor is that he was impressed by a convoy of HMMWVs that he saw while filming Kindergarten Cop.) Three years later, AM General sold the brand name to General Motors. Even though they continued to manufacture the vehicles, GM took over the responsibility for marketing and distribution.

Over the next two years, GM introduced the H2 and H3, and renamed the original to H1. AM General continued to build the H1 until the line was stopped in 2006, and is contracted by GM to build the H2. The H3 is constructed in Shreveport, LA, in the same plant as the Chevrolet Colorado and GMC Canyon pickup trucks.

Hummer took on the international market in 2006, with select importers in Europe and other markets. The international version H3 is now being produced in Port Elizabeth, South Africa, for local use as well as export to Australia, Europe, Japan, and the Middle East. In addition, the H2 has been produced in Kaliningrad, Russia by Avtotor since June 2004, strictly for local use. Today, the Hummer is represented by roughly 300 dealers in 34 countries. A little more than half of those dealers are in the US.