The first character you meet starts out as a mockingbird. In the beginning of the book, Scout is an innocent, six year old child whose wholesome heart had never had an encounter with evil. As the book continues, her innocence is slowly taken away. Her meetings with racial prejudice take large bites out of her purity. By the end of the book, Scout's naïve point of view is now is closer to an adult's understanding of the prejudicial society she lives in. However, some of Scout's innocence is still there. It was protected by the moral voice of her father, Atticus.

Dill is also a mockingbird. He represents child innocence. He only provides excitement and adventure into the lives of Scout and Jem. Still, he is unfortunate. His family did not care for him so he is moved from family member to family member. He is a lonely child without "anywhere to run off to" but still he makes others feel less lonely.

Atticus is one of the few main characters that is not a mockingbird. He is pure but he has lost his innocence. Atticus is the conscience and the warden of the "mockingbirds" in To Kill a Mockingbird. He is the protector of the innocent. He shields his children and tries to protect them from the evils by giving them morals. He also tries to guard Tom Robinson from being killed.

Arthur "Boo" Radley is another Mockingbird. The only thing mockingbirds ever do is "sing their hearts out for us" and Boo does nothing but that. All he does is leave Jem and Scout presents and saves their lives while risking his own. Even though Boo Radley's heart is pure, his innocence is still damaged by his abusive father and he is "killed" many times. It is noticed by Scout that to hurt Arthur it is"sort of like shootin' a mockingbird.

Tom Robinson is another example of a mockingbird. Like Arthur, Tom never harms anything or anyone. The only mistake Tom made was to help Mayella and chop wood for her. Mayella accused Tom of raping her. When asked if Tom was the man who raped her, she replied while under oath at Tom's trial and said that he "most certainly is". He is clearly innocent, but still, those around him must sin and to kill a mockingbird. "Tom was a dead man the minute Mayella Ewell opened her mouth and screamed". He became a dead mockingbird. Even as a symbolic mockingbird, Tom Robinson was not accorded the same dignity and respect as the other "mockingbirds" in the novel.

Boo Radley is also a symbol of the development from innocence toward a grown-up moral perspective. Boo is a source of childhood superstition. Boo is an intelligent child ruined by his father. He is also one of the books most important symbols in the book.