- Elsie, Stoneman's daughter (Lillian Gish) - The ony daughter of the Stoneman family and Ben's Love Interest. A loyal and dutiful Ingenue, Elsie becomes a Damsel in Distress during the film's climax.
- Flora Cameron, the pet sister (Mae Marsh, as a child by Violet Wilkey) - The younger daughter of the Cameron family, Flora is a Genki Girl and The Cutie. To escape from Gus, she commits suicide by jumping off a cliff.
- Col. Ben Cameron (Henry Walthall) - Despite being third-billed, Ben is actually The Hero, at least according to the film's morals. He is the oldest son of the Cameron family and the only one to survive the war, becoming a colonel in the Confederate Army. After the war, "the Little Colonel", as he's referred to a number of times, founds the Ku Klux Klan and leads the Klansmen when they become The Cavalry at the end of the film.
- Margaret Cameron, elder sister (Miriam Cooper) - The older daughter of the Cameron family. Margaret is a Southern Belle and Phil's Love Interest.
- Lydia, Stoneman's Mulatto housekeeper (Mary Alden) - Using a Wounded Gazelle Gambit, Lydia elicits Stoneman's sympathies and becomes a Lady Macbeth. Their interracial sexual relationship is considered an unholy abomination by the film.
- Hon. Austin Stoneman, Leader of the House (Ralph Lewis) - Elsie's father and Speaker of the House of Representatives in the U.S. Congress. He is the movie's Big Bad, wanting to severely punish the South after the war. Stoneman claims to believe in racial equality, but it's shown that this is actually just a cover for his evil plan to destroy the South by putting the blacks in charge. He seems to be a Composite Character of various radical Reconstruction leaders, but comes off especially strongly as a No Celebrities Were Harmed version of Thaddeus Stevens.
- Silas Lynch, Mulatto Lieut. Governor (George Siegmann) - Lynch is The Dragon and eventually a Dragon-in-Chief. Under Stoneman's radical leadership, the vote is shown being taken away from whites and given exclusively to blacks. This allows Lynch, an associate of Stoneman, to cheat his way to victory in an election by promising "equality". Once in power, he rules with an iron fist, introducing such "tyrannies" as interracial marriage and saying he wants to create a "Black Empire". At the end, he tries to "marry" (read: rape) Elsie.
- Gus, a renegade negro (Walter Long) - Guess how enlightened the portrayal of this character is. A would-be rapist and professional racist caricature, Gus is played by a white actor in blackface. The KKK kills him and leaves the corpse on the doorstep of Governor Lynch's house.
- Tod, Stoneman's younger son (Robert Harron) - The younger son of the Stoneman family.
- Jeff, the blacksmith (Wallace Reed)
- Abraham Lincoln (Jos. Henabery) - Come on, you know who this guy is. Lincoln is portrayed as wanting to treat the defeated South with clemency, a policy opposed by the radicals like Stoneman. Ben is saved from the gallows when Lincoln gives him a presidential pardon. When he is shot by John Wilkes Booth, Lincoln's plans for leniency die with him and the South is shown mourning the loss of their ally in the White House. The movie makes no mention of Lincoln freeing the slaves and instead acts as though saving the union was his only motivation.
- Phil, Stoneman's elder son (Elmer Clifton) - The older son of the Stoneman family. He serves in the Union Army with distinction.
- Mrs. Cameron (Josephine Crowell) - Matriarch of the Cameron family.
- Dr. Cameron (Spottiswoode Aitken) - Patriarch of the Cameron family.
- Wade Cameron, second son (J. A. Beringer) - Wade is the middle son of the Cameron family. He dies in the war.
- Duke Cameron, youngest son (Maxfield Stanley) - Duke is the youngest son of the Cameron family. He also dies in the war.
- Mammy, the faithful servant (Jennie Lee) - A Mammy, obviously
- Gen. U.S. Grant (Donald Crisp)
- Gen. Robert E. Lee (Howard Gaye)
Characters / The Birth of a Nation (1915)