Ned is a small, highly intelligent Navajo youth who is forced to attend a mission school where administrators suppress his language and culture. Despite these harsh assimilation efforts, he secretly retains his Navajo tongue and excels academically. He enlists in the US Marines as a teenager to serve as a code talker, using his native language to transmit classified information during the Pacific island campaigns. He deeply values his cultural heritage and performs morning rituals with corn pollen while deployed overseas.

Georgia Boy is a tall white Marine with blond hair and blue eyes who meets Ned during basic training. Because he struggles with literacy, he relies on Ned to read his mail from home. He is good-natured and frequently fights alongside the Navajo Marines during Pacific island campaigns, proving to be a fiercely loyal ally in combat.

Smitty is a white Marine who frequently serves alongside Ned Begay during the Pacific island campaigns. He receives a covert assignment to stay close to Ned in battle to ensure other American soldiers do not mistake the Navajo code talker for a Japanese combatant. He performs this duty diligently while building a genuine camaraderie with Ned.

Johnny is an older Navajo boy from the boarding school who becomes a Corporal in the Marines. He stays stateside initially to instruct new Navajo recruits at Camp Elliott. He commands immediate respect from both white officers and Navajo civilians through his serious, stately bearing and military professionalism.

He is the only member of Ned's family who previously attended a mission school. He believes that understanding white American culture is a necessary survival tool for the Navajo people. He advises his nephew to learn English without abandoning his cultural roots.

Mr. Reamer is a white administrator at the Rehoboth Mission boarding school. He incorrectly believes he understands the Navajo language and arbitrarily assigns English names to the Indigenous children. He violently enforces the English-only rules by washing students' mouths out with harsh soap.

Hosteen is a respected Navajo elder and "singer" who performs traditional ceremonies for the community. He operates a freighting business and forms a warm bond with Ned before the boy departs for military service, nicknaming him "Ant" due to his strength and size.

John is a Navajo Marine assigned to stay in the United States to help train new code talkers. He works alongside Johnny Manuelito at Camp Elliott to teach the classified code vocabulary to incoming recruits like Ned.

Jacob is a Navajo man working at the Rehoboth Mission school stables. He wears his hair short and dresses in white American clothing, serving as a gentle interpreter for the frightened Indigenous children during their first day orientation.

Frank Shinn is a Marine recruiter whose serious bearing, crisp uniform, and office decorations inspire young Navajo men to join the military. He delivers a rousing speech that galvanizes Ned's desire to enlist immediately.

Bill is a fellow Navajo Marine in Ned's platoon. He provides comfort during their daunting sea voyage by reminding Ned to look up at Father Sky for protection against deep-water fears.

Sam is an experienced code talker who has already seen combat in the Pacific. He shares harrowing stories with incoming recruits about the realities of battle, dead bodies, and the initial confusion surrounding the Navajo code.

Bill is a veteran Navajo code talker who helps orient the new arrivals in Hawaii. He explains how American officers initially mistook their Navajo radio transmissions for Japanese frequencies during early battles on Guadalcanal.

He is a white commanding officer who tasks the Marines with surviving a harsh desert trek using only one canteen of water. Unlike the resourceful Navajo soldiers who locate water inside cacti, he eventually collapses from dehydration.

Gene is an indigenous Solomon Islander who escaped the occupying Japanese forces. He communicates with Ned in pidgin, sharing a mutual understanding of what it means to have one's homeland overtaken by foreign powers.

Charlie is a Navajo code talker who is mistakenly presumed dead on the battlefield. His fellow Marines take his dog tags and cover him, but he miraculously reappears weeks later having survived his injuries.

He is a favorite instructor of the code talkers during their training at Camp Elliott. The Navajo recruits feel comfortable enough around his easygoing nature to pull practical jokes on him.

John is a particularly recalcitrant Navajo boy at the boarding school who refuses to stop speaking his native language. As punishment, school officials chain him to a wall in a stone basement and feed him only bread and water.

Alex is a code talker who shares a harrowing story about the campaign on New Britain Island. An American soldier mistook him for an enemy combatant and nearly bayoneted him before another Marine vouched for his identity.

Danny is a code talker who brings a rare moment of lightheartedness to the grim realities of Saipan. He uses a slingshot to kill chickens and makes a stew to share with his surprised non-Indigenous counterparts.