Who is the main character in "The Stanley Parable"?

The main character in "The Stanley Parable" is indeed Stanley himself. As the player controls Stanley, they navigate through an office building, making choices that determine the outcome of the game. The narrative revolves around Stanley's journey, exploring themes of free will, determinism, and the nature of storytelling. Hence, the answer is Stanley because he is the protagonist and the player's avatar in the game's world.