Connie is a fifteen-year-old girl whose primary interests are popular music, her appearance, and spending time with boys at the local drive-in restaurant. She lives in a suburban home with her parents and older sister, feeling constantly criticized and misunderstood by her family. To escape this domestic frustration, she cultivates a separate, more mature persona when out with her friends, filling her days with romantic daydreams inspired by the songs she listens to on the radio.

Arnold Friend is a mysterious older man who drives a distinctive gold convertible adorned with seemingly outdated slang and painted numbers. He dresses in clothing meant to mimic youth culture, though his poorly applied makeup and awkward posture suggest he is much older than he pretends to be. He speaks with a sing-song rhythm that mimics the popular music on the radio and displays an uncanny, unexplained knowledge of the local teenagers.

Connie's mother is a homemaker whose own beauty has faded over the years, leading to a lingering resentment. She frequently nags Connie about her vanity and behavior, creating a tense atmosphere in the house. She often compares Connie to her older, more reliable sister, June, establishing a dynamic of favoritism that frustrates her younger daughter.

June is Connie's twenty-four-year-old sister who works as a secretary at the high school Connie attends. She is described as plain, chunky, and steady, standing in sharp contrast to Connie's youthful vanity and rebelliousness. She conforms willingly to expectations, earning their mother's approval and Connie's hidden disdain.

Connie's father is the primary breadwinner of the family, spending most of his time at work. When he is at home, he remains emotionally distant and prefers to read the newspaper rather than talk to his daughters or wife. His absence leaves Connie without a strong paternal figure or meaningful adult supervision.

Ellie is Arnold Friend's strange, quiet companion who accompanies him during his sudden visit to Connie's house. He appears to be an older man, much like Arnold, but remains in a passive daze. His primary action is holding a transistor radio close to his ear, listening to the same music broadcast that plays inside Connie's home.

Betty is Connie's best friend and primary companion during the summer evenings. Together, they frequent the local drive-in to listen to music and socialize with older boys. She provides Connie with an alibi and a sense of camaraderie during their rebellious outings.

Eddie is a boy Connie meets at the drive-in burger shop during one of her summer nights out. He provides Connie with the romantic attention she seeks, taking her away from her friend Betty for several hours. To Connie, he represents the exciting, mature world of casual dating that she actively pursues.