Matthew Harrison Brady
Matthew Harrison Brady has run for the Presidency of the United States three times—all unsuccessfully. But, that does not detract from his power as an orator and a politician. His experience with national politics has made him enjoy being in the spotlight, especially hearing the sound of his own voice and the adulation of an audience of devoted followers. Despite his losses in three national elections, Brady remains popular among the rural citizenry because of his staunchly conservative and fundamentalist interpretation of the Bible. Although it is never expressly stated, there is a suggestion that Brady will use the publicity of this trial to launch a fourth run for the country's highest office.

Sarah Brady
Although she is Brady's wife, she seems more like his mother. She is constantly looking out for his welfare, reminding him not to overeat, to watch his activity level, to take a nap, and to be careful of the "treacherous" night breezes. She gathers him into her arms and comforts him after his humiliation at the hands of Drummond at the end of Act II.

Rachel Brown
Rachel Brown is, like her accused boyfriend, Bert, a schoolteacher. She is also the daughter of the fiery Reverend Brown, a staunch defender of creationism. Rachel is squarely in the middle of the central argument of the play. If she sides with Bert because she loves him, she abandons her father and her religious faith. If she sides with her father's beliefs, she deserts the man she loves. A kind and gentle person who would rather give in than fight, Rachel must confront her own beliefs and doubts and discover what is most important in her life.

Reverend Jeremiah Brown
Reverend Brown is the voice of unyielding fundamentalism. If Bert is the representation of freedom of thought, Brown is his opposite. He believes that everything in the Bible is true "as written" and that anything that calls that truth into question is blasphemy. When Rachel protests his damnation of Bert during an impassioned sermon in Act II, Reverend Brown's religious fervor provokes him to curse his own daughter.

Bert Cates
Bert Cates is a quiet, reserved schoolteacher. Even though he disagrees with the Reverend Brown's view of religion, Bert taught evolution because he thought that it was unjust to keep new ideas from people simply because they might be in conflict with someone's religious views. He is not a rabble-rouser. In fact, he does not like all the hoopla his case has stirred up and nearly admits defeat so that he can return his life to normal.

Henry Drummond
The attorney for the defense, Henry Drummond, has defended some of the most notorious criminals in America. His courtroom demeanor—passionate, charming, and witty—seems at odds with the quiet and reserved behavior we see in private. He sees the law as a vehicle to search for the truth. He has the heart of an idealist but knows full well the reality of the law. His purpose in coming to Hillsboro is not to represent a schoolteacher who has broken a law but to defend the rights of an individual to think and reason without interference from the government.

E. K. Hornbeck
A cynical big-city reporter, Hornbeck enjoys lampooning the simple life of Hillsboro as well as their skeptical view of evolution. He takes particular pleasure in skewering Brady and his ideas. He views himself as the sole possesor of the "real" truth and scoffs at any and all who don't see the world as he does. As an element in the play itself, Hornbeck represents the "intellectual elite," while, at the same time, he serves as the comic relief.