The ZGMF-X09A Justice Gundam is a mobile suit introduced in Mobile Suit Gundam SEED and it is piloted by Athrun Zala.

One of ZAFT's five ZGMF-X Gundam units produced in CE 71 using technology derived from the four captured Alliance's Gundam, the Justice Gundam's main feature is the Fatum-00 unit on its back. This complex armament unit normally serves as the main thrusters, granting overwhelming acceleration as well as mobility when deployed horizontally and this configuration is also known as 'High-Mobility Aerial Tactics (HiMAT) Mode'. It also grants flight capabilities in the atmosphere and can be deployed as a separate unmanned unit or a subflight unit. It is armed with beam cannons and machine guns.

Other weapons of the Justice included beam sabers, beam rifle, shield, beam boomerangs and head-mounted CIWS guns. In comparison to the other ZGMF-X Gundam units, the Justice's armament is relatively simple and pales in firepower compared to its sibling, the ZGMF-X10A Freedom Gundam. However, the Justice's true value lies in its incredible mobility and the various tactics it can employ using the Fatum-00. It can also dock with a support unit, the METEOR unit, for heavier firepower and greater speed, and has an advanced targeting system, the Multi Lock-On System, which allows it to fire at multiple enemy units simultaneously.

Justice also has a tall sensor spine on the top of its head, similar to that of the GAT-X303 Aegis Gundam, and this enhances its ability to collect information in the battlefield. It is designed to be operated alongside the Freedom and for this purpose, the warship Eternal is designed specifically to maintain both suits. Like the four other ZGMF-X Gundam units, Justice is armored with Phase Shift Armor and has virtually unlimited combat endurance as it is powered by a nuclear reactor thanks to the Neutron Jammer Canceller.