Billy Jack is a "mixed-race" Navajo,[3] a Green Beret Vietnam War veteran, and a hapkido master.
Jack defends the hippie-themed Freedom School (inspired by Prescott College) and students from townspeople who do not understand or like the counterculture students. The school is organized by its director, Jean Roberts (Delores Taylor). One of the troubled youths is a girl named Barbara, who became pregnant and was abused by her father.
A group of children of various races from the school go to town for ice cream and are refused service and then abused and humiliated by Bernard Posner (David Roya), the son of the county's corrupt political boss Stuart Posner (Bert Freed), and his gang. This prompts a violent outburst by Billy. Billy goes through a Navajo initiation where he is bitten purposely by a large rattlesnake, so that he would become the blood brother to the snake, and survives the ordeal. Meanwhile, Barbara loses her unborn child, when the horse she was riding stumbles on a rock, causing her to fall off the horse. Following an incident involving Jean, Billy gives Bernard a choice of either receiving a dislocated elbow, or driving his Corvette into the lake; Bernard does the latter. Later, Jean is kidnapped and raped by Bernard, who also murders a Native American student. Billy confronts Bernard, whom he catches in bed with a 13-year-old girl, and sustains a gunshot wound before killing him with a hand strike to the throat. After barricading himself following a climactic shootout with the police and pleading from Jean, Billy Jack surrenders to the authorities in exchange for a decade-long guarantee that the school will be allowed to continue to run with Jean as its head. As Billy is driven away in handcuffs, a large crowd of supporters raise their fists as a show of defiance and support.