The FA-78 Full Armor Gundam (Thunderbolt Ver.) is a mobile suit that appears in the manga Mobile Suit Gundam Thunderbolt and its animated adaptation. It is piloted by Io Fleming.

A heavily armored and highly maneuverable Gundam-type mobile suit deployed by the Moore Brotherhood. There was another type of Full Armor Gundam with similar model number, the FA-78-1, but it had different details and equipment. Both mobile suits were developed under the ‘Full Armor Operation’, and their differences were a result of experimenting with various systems and equipment.

The Full Armor Gundam was fitted with numerous pieces of body armor, a large backpack and had much more weaponry than other mobile suits of its time. Like other mobile suits of the Moore Brotherhood, the Full Armor Gundam had special seals on its joints and large backpack to protect them from the debris drifting in the Thunderbolt Sector. Besides the standard beam sabers, it was also armed with a twin beam rifle, five rocket launchers, a large beam cannon, a 6-tube missile pod and numerous missiles stored in various body armor.

Using the two sub-arms on the large backpack, the machine could wield up to four shields, greatly increasing its defensive capabilities. To prevent the weight of the added equipment from reducing the mobile suit's mobility, thrusters and apogee motors were installed on the shoulders, legs and large backpack. The large backpack was also fitted with two rocket boosters, and the Full Armor Gundam's total thrust was considered to be comparable to a high mobility-type mobile suit.

The Full Armor Gundam's added body armor, the large backpack and most of the weaponry could be purged when they are damaged or not required, reducing dead weight. After witnessing the power of the Moore Brotherhood's Full Armor Gundam, the Zeon's Living Dead Division, which was operating in the same area, decided to deploy the MS-06R Zaku II High Mobility Type (Reuse "P" Device).