One of King's most significant talents as a writer is his skillful portrayal of characters. In this novel, narrated through the monologue of a single character, King expertly captures the essence of Dolores's personality. As she shares her story at her own pace, despite the police's impatience, readers gain insight into the depth and complexity of her bravery. Dolores consistently recounts her life, her loves, her lapses, her wrongdoings, and her motivations. She is irritable, crude, vulgar, fiercely protective, earthy, vivid, kind-hearted, believable, and captivating. Through her genuine voice—raw, unrefined, tormented, and unforgettable—Dolores Claiborne emerges as an almost heroic figure.

In contrast, Joe St. George, Dolores's husband, is portrayed as a one-dimensional, boorish, insensitive drunk. He is physically abusive, has voyeuristic tendencies towards their compassionate daughter, and emotionally damages the mother-daughter bond between Dolores and Selena. The only positive memories Dolores shares of Joe are from their early courtship and marriage, which, in hindsight, appear ironic.

Vera Donovan, when compared to Dolores, is depicted as a bitter and tragic character. Like Dolores, she understands that "men have accidents all the time." She is an independent woman who made the painful choice to murder her husband and spends the remainder of her life dealing with the consequences of her actions. Although her husband's infidelity is a silent secret within their marriage, his death in a car accident is a relief to her. However, her children blame her for the infidelity and the accident. A year later, they die in another car accident. Vera spends the rest of her life fabricating stories about her children as if they were living yet estranged from her. Dolores describes Vera as a "bitch" due to her obsession, demanding nature, and pathological anger. She is also sly, vicious, and punitive. Ultimately, she is a pitiable, deteriorating, lonely woman, losing her sanity and afraid to live or die. Despite Vera's progressively erratic behavior, Dolores confesses she still harbors some affection for Vera: "I felt something for that bitch besides wanting to throttle her. After knowing her over forty years, it'd be goddam strange if I didn't." Vera, in turn, has shown Dolores loyalty with subtle affection, by intuitively understanding Dolores's domestic struggles and assisting with her family issues as much as her sense of propriety would permit.