It's the early 15th century and the English rule much of France during the bloody Hundred Years' War. Charles VII (JOHN MALKOVICH) of France will not abandon the kingdom that his rightly his, but realizes he can't be crowned king until the English are driven from Rheims.
He gets his chance when he receives a message that he's to be visited by a young woman who claims to be a messenger from God sent to aid him and the French. She's Joan (MILLA JOVOVICH), a devoutly religious teenager who several years earlier witnessed the English sack her village and rape and kill her older sister. Having experienced various visions of God that included her finding a battle sword, Joan knows that her mission is to see that Charles is crowned king by driving the English from France.
While his aides discourage him from meeting this woman they believe to be a possible assassin, Charles' regal mother-in-law, Yolande of Aragon (FAYE DUNAWAY), persuades him to. As such, Charles is impressed that the young woman is able to identify him from a large crowd despite his captain, Jean D'Aulon (DESMOND HARRINGTON), posing as him.
Believing that he might as well give Joan a shot, Charles sends her off to fight with his half-brother, Dunois (TCHEKY KARYO), a strategy-based officer who doesn't believe in Joan's more impulsive battle tactics. Nonetheless, Joan's efforts of leading the French result in victory after victory, her becoming a hero, and Charles eventually being crowned King of France.
Yet Charles soon loses interest in raging war and cuts off her military aide despite her continued efforts to drive the English from her homeland. Eventually captured and brought up on charges of heresy before an ecclesiastical court, Joan is taunted by visions of her Conscience (DUSTIN HOFFMAN), who makes her begin to question her previous visions and religious faith.