Billie Jo is a thirteen-year-old girl living on a struggling farm in the Oklahoma Panhandle during the Dust Bowl. She excels at school and possesses a deep passion for playing fierce, energetic tunes on the piano. She manages a complex relationship with her emotionally distant parents while eagerly awaiting the birth of a new sibling. Her musical talent provides a creative outlet as the environmental and economic conditions worsen around her.

Ma is Billie Jo's hardworking, pragmatic mother who is expecting a baby after years of hoping for another child. Though she rarely shows outward affection or praises Billie Jo's academic achievements, she is deeply connected to her family. She possesses a spellbinding talent for playing the piano and lovingly tends to two apple trees she planted when she first married.

Bayard is a determined, hardworking farmer devoted to his Oklahoma land and his family. A veteran of the Great War, he insists on continually planting wheat despite the severe droughts devastating the region. He shares an emotional reticence with his daughter, communicating more through stubborn action than spoken words.

Mad Dog is a handsome, sixteen-year-old local boy who works the land and possesses a remarkably smooth singing voice. Given his nickname because of a childhood biting habit, he frequently performs at the Palace Theatre alongside Billie Jo. He stands out to Billie Jo by treating her with consistent kindness and acting like a true peer.

Arley is the local school music teacher and a popular song promoter. He recognizes Billie Jo's extraordinary talent and frequently invites her to perform piano with his band, the Black Mesa Boys. He provides her a much-needed creative outlet and a modest source of income during desperate economic times.

Vera is Arley Wanderdale's wife who helps organize community events and shows. She travels with her husband's band and coordinates activities like the town's dance revue, providing a steady presence during their local tours.

Franklin is Billie Jo's eagerly awaited baby brother. Named after President Roosevelt, he represents a source of new life and optimism for the Kelby family as they endure the harsh, unrelenting conditions of the Oklahoma drought.

Livie is Billie Jo's best friend at the start of the novel. She moves away from the Panhandle with her family in search of better opportunities, leaving Billie Jo feeling lonely and restless in the dusty town.

Miss Freeland is Billie Jo's schoolteacher who provides guidance, education, and deep empathy to her students. She teaches the children about the agricultural history and ecological causes of the Dust Bowl, and she shows remarkable compassion to transient families passing through the area.

Mr. Hardly is the proprietor of the local general store in Joyce City. Known for being stingy and occasionally shortchanging his customers, he serves as a fixture in the struggling local economy where supplies are constantly scarce.

Aunt Ellis is Bayard Kelby's older sister who lives in Lubbock, Texas. She is one of the few living relatives the Kelby family has outside of the immediate household, representing a distant and unappealing alternative home for Billie Jo.

Doc Rice is the local physician who tends to the medical needs of the community. He treats serious injuries, dispenses practical advice, and continuously urges the stubborn farmers to address health conditions exacerbated by the harsh environment.

Louise is a teacher who instructs the night school classes. She enters the Kelbys' lives as a steady, understanding presence who respects their family boundaries and history without trying to force her way into their established routines.

Reverend Bingham is the local minister in the community who presides over church services and ceremonies. He attempts to provide spiritual comfort to the townspeople, though his words sometimes feel empty to those experiencing profound grief.

Joe is a neighboring cattle rancher struggling to keep his livestock alive as the drought destroys the available grazing land and water sources. His failing ranch serves as a stark warning about the unyielding environment.

Dewey is a local government agricultural agent who monitors the struggling crops and must occasionally take grim, practical measures to deal with starving livestock on local ranches.

Coach Albright is the school basketball coach who encourages Billie Jo to join the team, noting that her height and long fingers would make her an excellent player.

Birdie Jasper is a fellow performer in the local talent competition. She is fiercely competitive and displays outward jealousy toward Billie Jo's musical success, attributing Billie Jo's achievements to pity rather than talent.

Haydon P. Nye is an elderly local resident who settled in the Oklahoma Panhandle back when it was still open plains filled with buffalo, wolves, and wild prairie grass. He represents the historical memory of the untouched landscape.

Fonda Nye is Haydon P. Nye's devoted wife, representing the older generation of original settlers in the Panhandle region who have watched the land transform over decades.

Sheriff Robertson is the local law enforcement officer who handles illegal operations in the county. He shows community spirit by donating confiscated goods to the school rather than letting them go to waste.

Ashby Durwin is a local man caught running an illegal whiskey-making operation. He represents how some residents turn to illicit means to make money during the severe economic depression.

Rush is a local resident who partners with Ashby Durwin to run an illegal whiskey operation, seeking to profit outside the failing agricultural system.

Mr. Haverstick is a neighboring farmer who shares the widespread agricultural struggles of Cimarron County. His tiny crop yield sets a grim benchmark for the other local farmers.

Pete Guymon is the local supply driver who ensures goods reach Mr. Hardly's store. His continuous exposure to the elements makes him vulnerable to the severe health risks of the dust storms.

James Kingsbury is a photographer for the Toronto Star who travels to Cimarron County to capture images of the dust storms. His presence makes the locals wonder how the rest of the world perceives their struggles.

Mrs. Brown is a local resident who cultivates a special cereus flower that blooms only briefly at night. Her plant draws the attention of neighbors seeking brief moments of beauty in the harsh environment.