The unnamed boy serves as the book's central figure and is the only character fully developed. Initially depicted as a solitary child around six or seven years old, he deeply admires his father and enjoys hunting with him and their dog, Sounder. Instead of describing the boy directly, Armstrong uses his thoughts and observations to illustrate that he is strong, curious, and kind-hearted. Coming from an illiterate family, the boy yearns to learn how to read. After Sounder is shot, the boy shows his dedication by comforting and aiding the dog. When his father is unjustly imprisoned, he courageously leaves his mother and their small cabin to search for his father and pursue education.

Eventually, the boy encounters a teacher who becomes a mentor and father figure. As he matures into a selfless, industrious teenager, he takes responsibility for his mother and siblings. Despite his progress, he remains connected to his origins, returning home each summer to work the family farm and contribute to the rent. The boy faces pain and setbacks with quiet dignity and resilience.

The brave and loyal dog, Sounder, is described as "a mixture of Georgia redbone hound and bulldog." Both Sounder's bark and spirit are grand and noble. Armstrong illustrates Sounder's melodious bark as echoing throughout the countryside: "But it was not an ordinary bark. It filled up the night and made music as though the branches of all the trees were being pulled across silver strings." A skilled hunter, Sounder suffers a debilitating gunshot wound while courageously trying to protect his master during the father's arrest. By drawing parallels between Sounder's and the father's fates, Armstrong highlights the brutal treatment of humans in the racist early twentieth-century South. Both characters endure unprovoked violence that ultimately cripples and kills them.

The boy's mother is portrayed as a resilient, hard-working woman who believes that fate is an unstoppable force. She takes in laundry and shells walnuts to sustain a modest livelihood. Reluctant to see her son leave home, she discourages him from learning to read. She often hums or sings the sorrowful song "That Lonesome Road." A limited and melancholic figure, she speaks in short, terse sentences like everyone else in the story and tries to conceal her emotions.

The father appears only at the beginning and the end of the story. Initially, he is depicted as a strong, resourceful, and loving man who finds joy in hunting. He hunts not merely for sport but to provide food for his family. As the story begins, game is scarce, and the family is starving. In desperation, the father steals a ham and sausages to feed them. His deep love for his family drives him to risk his own freedom so they can eat. Brutally arrested and humiliated in front of his family, he feels too ashamed to speak to his son when the boy visits him in the county jail. By the story's end, the father returns, crippled from a mining accident after years of hard labor on a chain gang. Broken by society's harsh punishment for a minor crime, he dies while hunting with Sounder.

Armstrong uses the young boy and his family to highlight the evils of racism and poverty. Themes of social injustice and unnecessary cruelty are developed through detailed and realistic descriptions of the father's arrest, the boy's jail visit, and the father's crippling incident. The boy's courage in facing racism, his resilience against adversity, his selfless love for his family, and his passion for learning are qualities Armstrong emphasizes as essential for human survival. The boy learns to read to combat his loneliness and break the chains of ignorance that imprison his family. Consequently, the book also explores the power of literature and stories to provide comfort and help people cope with hardships.