Antagonist
Character Role Analysis
The Court
Normally, we wouldn't think of an abstract entity as an antagonist, but The Trial elevates a whole bureaucracy to the status of primary antagonist. The nature of a bureaucracy is that it's a network of individuals who are caught up in an organism that is vastly more than the sum of its parts; every guard, inspector, magistrate, and court official fulfills their function, not out of a personal passion, but for the good of the bureaucratic organism of which they're a part. K. must grapple with the numerous tentacles of this vast entity throughout the course of the novel.