The Underworld Army is one of the main armies you must fight against in Kid Icarus, Kid Icarus: Of Myths and Monsters and Kid Icarus: Uprising. The Underworld Army consists of a lot of enemies that Pit encounters throughout the games, and is run by Hades, who lets Medusa control the forces as a distraction for everyone else.
 Kid Icarus
In Kid Icarus, the Underworld Army is under control by Medusa. After successfully storming Palutena's Palace and capturing the Overworld and Skyworld, the Underworld Army was set to guarding the areas. They are destroyed however by the protaganist Pit, who was captured and held in the deepest recesses of the Underworld.
 Of Myths and Monsters
In Kid Icarus: Of Myths and Monsters, the Underworld is once again stretched out among the four areas, most likely left there after Medusa's defeat.
 Kid Icarus: Uprising
In Kid Icarus: Uprising, Medusa is the leader of the Underworld Army at first. She has her forces attack and harass Pit throughout the first nine levels. At the conclusion of Chapter 9 however, it is revealed Hades is the Underworld Army's true leader. His forces harass Pit too, along with the Forces of Nature and the Aurum.
He is finally defeated in Chapter 25, where Pit has to fight him with the Great Sacred Treasure, and the Underworld Forces most likely retreat back to the Underworld to wait for a possible ressurection of their leader.
The following are commanders of the Underworld Army:
 Important figures
The following are important figures in the Underworld Army:
- Great Reaper
 Underworld Army Opposers
- Palutena and the Centurian Forces oppose Hades due to his disregard for life, and her vendetta against the Underworld in the past.
- The Forces of Nature led by Viridi oppose Hades and his army due to Hades' nonchalant way of playing with souls and the celestial balance.
 Underworld Army Enemies
The following shows all the enemies in the Underworld Army:
- Brawny Claws
- Eggplant Wizard
- Fire Wyrm
- Fort Oink
- Mega Mussel
- Tempura Wizard
- Wave Angler
- Zik & Zak