The RGM-79 GM (aka GM, pronounced Jim) was the first mass-produced mobile suit of the Earth Federation. It first appears in Mobile Suit Gundam.

The RGM-79 GM is a mass-produced mobile suit based on the RX-78-2 Gundam. Its basic frame is easily adaptable to modifications into mission specific GM models, and has a fairly high level of mobility, for the time, both on Earth and in space. It has a maximum acceleration of 0.94 Gs in space, which is better than the Gundam's and roughly twice of the Zaku's. On Earth's surface, the GM is also faster than the Zaku II. The armor of the GM uses Titanium Alloy, a sturdy metal that could be refined more quickly and easily than the Gundam's Luna Titanium Alloy. Although titanium alloy is less durable than Luna Titanium, it is also slightly lighter which reduces the GM's overall mass compared to the Gundam's and is still superior to the Zaku II's super-high tensile steel armor.

The GM was primarily armed with a beam spray gun, a less powerful version of the Gundam's beam rifle but could still destroy MS in one shot. Early in production, the beam spray gun had yet to be mass-produced so most GMs were equipped with various machine guns. These machine guns continued to be used by the GMs later, and the machine could also use the Gundam's beam rifle when required. It could also use a mass production version of the Gundam's Hyper Bazooka for heavier firepower. For close combat, the GM has a beam saber, and a shield similar to the one used by the Gundam. Commander units sometimes featured a second beam saber. Lastly, the GM has a pair of head-mounted 60mm vulcan guns for intercepting missiles, small vehicles or to stop enemy MS from closing in. From the GM started the RGM series that remained the mainstay of the Federation's mass production mobile suits until the end of the Federation itself.