Darth Vader's son is Luke, a four-letter name. Luke is a major character in the Star Wars franchise, first appearing in the original 1977 film. He is the twin brother of Princess Leia and the son of Darth Vader, the main antagonist of the original trilogy. Luke is a Jedi Knight and a hero of the Rebel Alliance, and is instrumental in defeating the Galactic Empire. He is also the protagonist of the original trilogy and the prequel trilogy.