A Thief is a class that is used in all Disgaea games. For many of the thieves, their main purpose is not for attacking, but rather for the purpose of Stealing, as they are the only class that can steal with up to a 99% chance.
- Main article: Thief (Disgaea)
The Thief in the first Disgaea had horrible Stats, Aptitudes, and Weapon Mastery levels, easily making it the worst class to try and train to keep levels up, as well as learning new skills in order to be able to defend itself. A level 200 Thief is required in order to unlock the Majin class in this game.
- Main article: Thief (Disgaea 2)
As well as now being female, the thief from Disgaea 2 also receivied better stats, aptitudes, and weapon mastery levels than its previous counterpart. On top of that, a thief's Lover in this game allowed it a better chance to steal items from enemies. What's more, a thief in Disgaea 2 is able to learn skills on its own. These skills do not cause any damage, but rather cause a status effect to one unit.
- Main article: Thief (Disgaea 3)
The thief in Disgaea 3 is much like the Disgaea 2 thief, save for now they have only two skills, 'Create Box', and 'Create Barrel'. A level 15 thief is required in order to unlock the Gunslinger and Gunner classes.
- Main article: Thief (Disgaea 4)
- Main article: Thief (Disgaea 5)
Makai Kingdom's thieves, much like the Disgaea 1 thieves, have bad combat stats, but they have a good Jump and Move stats, a large number of available item slots, and are the only class which can use UFO's, the weapon that is required in order to steal items from enemies.
While Phantom Brave did not have any 'thief' to speak of, the 'Bottlemail's that can be created could be considered the thieves of that game, since they have the highest 'steal' chance, along with the highest chance to take something back to Phantom Isle, but have some of the worst stats among all other creatable characters.
The Thief of Soul Nomad is known as the 'Bandit'. While it is unknown if a Bandit has a better chance of stealing from the enemy than any other squad, the Bandit is best known for having a high speed, causing most attacks to miss them, and also for its squad leader tactic of 'Fade Out', which makes it invisible to enemy forces until it attacks, uses a Gig Edict or another tactic, or an enemy steps next to them.
It's special attack when it is the leader is known as the 'Lupin Snatch', a possible tribute to Lupin III, a famous anime thief. The attack targets the enemy squad's leader.