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 technology of the RX-78-2 Gundam. The basic frame was suited for a fairly high level of mobility, for the time, both on Earth and in space while at the same time proved easily adaptable to modifications that could be developed into mission specific GM models.

The armor of the GM is a titanium alloy, a sturdy metal that could be refined more quickly and easily than the Gundam's Luna Titanium Alloy. Although titanium is less durable than luna titanium, it is also slightly lighter which reduces the GM's overall mass compared to the Gundam.

The GM was armed rather simply, with most of its weapons basically scaled down versions of that of the RX-78-2 Gundam . The GM was primarily armed with a beam spray gun, which was basically a downgrade in most aspects of the Gundam's powerful beam rifle. It did have the distinction still of being the first mass-produced beam weapon ever made - something the Zeon forces had yet to do. The beam spray gun had a much worse range than the beam rifles used by other Federation MS, but it could still destroy MS in one shot and was just as accurate and had a higher rate of fire and more ammo. The GMs also used 100mm and 90mm machine guns, the latter having less ammo capacity but a better armor penetration rate. Heavy weapons wise, GMs used remakes of the Gundam's 380mm Hyper Bazooka. For close quarters combat, the GM featured a single beam saber, although earlier models had the twin-saber backpack of the Gundam. Lastly, the GM had a pair of 60mm vulcan guns mounted in its head, which gave pilots backup firepower that was highly effective against aircraft and ground vehicles but woefully inadequate against mobile suits. Early in production, the beam spray gun had yet to be completely mass-produced so most GMs were equipped with machine guns.

By Operation Star One and Battle of Solomon, however, most the mobile suits used the beam weapon. It should also be noted that a small portion of the GMs stationed at the Federation General HQ in Jaburo also used the Gundam's beam rifle (These may have been either spare or left-over hardware from the initial V-Project Gundam prototypes however). From the GM will start the RGM series, developed from the Anaheim, that will remain the first choice as Federation's mass production mobile suits until the end of Federation it self.