John Grady is a sixteen-year-old rancher who deeply values the traditional vaquero lifestyle. Raised largely by his grandfather and ranch workers in San Angelo, Texas, he possesses immense skill as a rider and feels disconnected from his mother's desire to sell their land. Driven by a strict moral code and a romantic view of the world, he leaves his home behind to seek a true cowboy life across the border.

Lacey Rawlins is John Grady's pragmatic, sarcastic, and loyal best friend. Unlike his companion's romanticism, Rawlins views the world with a dry, matter-of-fact skepticism. He rides south seeking adventure and a fresh start, acting as a cautious counterweight to his friend's trusting idealism.

Jimmy Blevins is a young, prideful runaway claiming to be sixteen years old. Riding an expensive bay horse and carrying a unique pistol, he is impulsive, defensive, and fiercely protective of his belongings. His vulnerability prompts John Grady to look out for him despite Rawlins's strong misgivings.

Alejandra is the beautiful, headstrong daughter of a wealthy Mexican ranch owner. Educated in the city but preferring the country, she shares John Grady's profound love for horses. She pushes back against the strict, conservative gender expectations placed upon a woman in her social position.

Don Héctor is the wealthy owner of La Purísima, a sprawling cattle ranch in Coahuila. He is a commanding patriarch who takes immense pride in his land and his selective horse-breeding program. He demands total respect and operates with traditional views of authority and family reputation.

Dueña Alfonsa is Alejandra's grandaunt and the quiet power behind the social dynamics at La Purísima. Having lived through the bloody Mexican Revolution and suffered deep personal losses, she is highly educated, intensely pragmatic, and fiercely protective of her grandniece's reputation.

The Captain is a rural Mexican police authority figure who enforces his own version of order. Operating with near-total impunity in his district, he views outsiders with deep suspicion and uses intimidation to maintain control over those in his custody.

John Grady's father is a dying World War II veteran and former prisoner of war. Estranged from his wife, he has no legal claim to the family ranch to stop its sale. He shares a quiet, tender bond with his son, gifting him a high-quality saddle before they part ways.

John Grady's mother is an ambitious woman seeking a life beyond the isolation of the west Texas plains. She pursues a theater career in San Antonio and is determined to sell the inherited ranch, putting her permanently at odds with her son's traditional dreams.

Emilio Pérez is a powerful, wealthy individual who operates as a shadow authority within the penal system. Claiming to be a political exile, he uses his resources and influence to extort vulnerable inmates for protection money.

Abuela is an elderly Mexican woman who worked on the Cole family ranch. She was instrumental in raising John Grady during his parents' absences, providing him with maternal care and a deep connection to the land.

Mr. Franklin is the Cole family lawyer. He patiently explains the legal reality of the ranch's ownership to John Grady, representing the unyielding modern legal systems that are replacing traditional range rights.

Mary Catherine is John Grady's ex-girlfriend in San Angelo. Her decision to date an older boy with a car signifies the changing social dynamics in Texas that John Grady feels alienated from.

A remarkably fine, powerful bay horse that Blevins rides into Mexico. The animal's high quality immediately raises suspicions that it is stolen. The horse mirrors Blevins's own wild, skittish nature and becomes a central source of conflict.

Redbo is John Grady's reliable and trusted horse. As John Grady's primary companion on his journey into Mexico, Redbo represents the pure, uncorrupted natural world that John Grady idolizes.

A muscular, expensive racehorse purchased by Don Héctor to sire a new generation of working horses. Referred to as the caballo padre, the animal represents immense economic and patriarchal power on the ranch.