Who is the antagonist in 'To Kill a Mockingbird'?

Robert E. Lee "Bob" Ewell, Mayella's father, is the main antagonist. He is the one who accuses an innocent Negro of raping his daughter, gets him killed, and tries to kill Jem and Scout Finch.
Bob Ewell because he wrongfully accused tom Robinson of raping his daughter. He is an angry drunk and a racist.