The cavalier is a playable character class in the Dungeons & Dragons fantasy role-playing game, and the related Pathfinder Roleplaying Game. It is a mounted warrior mostly in the service of good.
The cavalier was introduced by Gary Gygax in Dragon #72 (April 1983). The cavalier later appears in the Advanced Dungeons and Dragons manual, Unearthed Arcana in 1985, which also made the paladin a sub-class of the cavalier class. The Samurai from Oriental Adventures and Knights of Solamnia from Dragonlance Adventures were also subclasses of cavalier. The cavalier (along with the barbarian) was revised in Dragon magazine 148, as, according to the author David Howery, "the cavalier described in Unearthed Arcana is complicated to play and overly powerful."
The cavalier appeared in The Complete Fighter's Handbook as a character kit, and again in Player's Option: Skills & Powers.
The cavalier appeared in Sword and Fist as a prestige class, and again in Complete Warrior.
The cavalier appeared as a type of paladin in the 4th edition Essentials rulebook Heroes of the Forgotten Kingdoms.