The Hummer H1 is a civilian off-road vehicle based on the M998 High Mobility Multipurpose Wheeled Vehicle (HMMWV, or Humvee), which was created by AM General. The vehicle was produced from 1992 through 2006, and was the first of what became the Hummer line.

Originally released in the civilian market in 1992, the Hummer H1 owed its birth to the popularity of photos from Operation Desert Storm and the enthusiastic campaign from actor Arnold Schwarzenegger, who personally owns several variants of Hummer vehicles. GM announced that 2006 would be the last model year for the Hummer H1, with production winding down in June 2006 due to a new emission law for Diesel engine vehicles which took effect in 2007.

Due to the requirement to meet EPA Tier 2 Bin 5 emissions standards, the cost involving recertification for a low volume civilian variant vehicle was not able to be justified. AM General currently has orders for an excess of 50,000 new HMMWVs to be produced between 2006-2009 for the United States Military. AM General also will continue to produce the H1, just not the Alpha. These vehicles will be sold through fleet sales.

Selling the H1s to friendly foreign governments and US organizations with emissions exemptions will allow AM General to not be subjected to the new 2007 Tier 2 Bin 5 emission rules and regulations. AM General has sufficient fleet orders to produce 600-800 units per year right now. The fleet H1s will end up using the standard 6.5L Turbo Diesel that has been commonplace in GM and commercial applications.

The Hummer H1 has three common variants: a convertible-like soft top, a four-door hard top pickup truck and a Wagon body version. Other less known variants include a two-door pickup truck and a four-door slantback. The convertible/soft top and the station wagon versions were the last ones available in the mass market. The two door and four door pickup versions are only available in fleet livery.

Currently, five engine types and three automatic transmission types can be found in Hummer H1s. The common engine/transmission combinations are:

• 6.2L GM Diesel V8/GM TH400/3L80 3-speed
• 6.5L GM Diesel V8/GM 4L80-E 4-speed
• 5.7L Vortec 5700 gasoline V8 TBI/GM 4L80-E 4-speed
• 6.5L turbo GM Diesel V8/GM 4L80-E 4-speed
• 6.6L turbo Duramax LLY turbo Diesel/Allison 1000 5-speed (model year 2006)

The Hummer H1 shares some common driveline parts with its HMMWV brethren. Items like brakes, axles, frame and major body panels (hood, tailgate and quarter panels) are identical between the HMMWV and the Hummer H1. All Hummer H1s and HMMWVs come off the same assembly line, and then civilian H1s get painted and finished in a separate building across the parking lot.