The Thief is a class that appears in the Disgaea series. Stealing is regarded as an advanced technique, so the Thieves' Guild is the largest in the Netherworld and is dedicated to preserving the advanced techniques of stealing. Thieves will steal anything by request and can even steal things not visible to the naked eye, such as emotions. Legend speaks of a legendary Thief King, though it is also suggested that this is a title taken on by skilled Thieves.
- 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.
- Main article: Thief (Disgaea 2)
The Thief in this game has better stats, aptitudes, and weapon mastery levels than the Disgaea incarnation. On top of that, a thief's Lover in this game allowed it a better chance to steal items from enemies. Thieves in Disgaea 2 are able to learn skills on their 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)
The Thief returns in Disgaea 4, with much of the same role as prior games.
- Main article: Thief (Disgaea 5)
The Thief returns in Disgaea 5.
Makai Kingdom Thieves, much like the Disgaea 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.
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.
Its 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.