Leo Borlock
Leo Borlock, the novel’s narrator and the viewpoint through which we see the other characters, is an introverted, observant, curious, and intelligent eleventh grader at Mica Area High School. Leo, an insightful character, seems to partly acknowledge the absurdity of his high school’s conformist environment—he notes that, somewhat ironically, kids are popular because they are not special or remarkable—yet overall, Leo accepts the sameness of high school. He appreciates the fact that there are prescribed rules of behavior to follow, and that by conforming to these rules, he is guaranteed acceptance by the larger group. Even in his one unique action before Stargirl’s arrival—starting the school TV show Hot Seat with his friend Kevin—Leo maintains his role as observer and interpreter. While Kevin acts as the show’s on-air host, Leo stays behind the scenes as the producer/director.

Leo begins to change as his relationship with Stargirl develops. She takes him out into the desert, where she tells him to quiet his mind and body and really see and appreciate the natural world around him. She encourages him to read the local section of the paper and take an active interest in his own community. As a result, Leo’s naturally observant nature becomes even more expansive and fine-tuned; looking back as an adult, he says he became a set designer when Stargirl taught him to truly see.

However, another aspect of Leo’s character is his cowardice and his fear of being rejected by the group. This fear ultimately leads him to reject Stargirl, a decision he regrets for the rest of the life. Leo is not a perfect character; rather, he faces the very human struggle between standing up for what he believes in and being accepted by the group. And like all humans, Leo sometimes makes the wrong decision, and sees his mistake too late.

Susan "Stargirl" Caraway
Stargirl Caraway is undoubtedly the central focus of Stargirl, even though readers are never privy to her interior thoughts. Stargirl is the catalyst for all the changes that occur in the novel, within Leo, in the high-school community, and in the town of Mica as a whole. Stargirl’s principal characteristic is her utter uniqueness, which can never be fully explained by her circumstances. Leo does discover that Stargirl was homeschooled, which explains her unfamiliarity with high school trends, and that her mother is a costume designer who provides the outlandish fashions she wears. However, when Leo meets Stargirl’s parents, he finds them surprisingly ordinary; thus, the author suggests that Stargirl’s individuality is an intrinsic part of her identity, not merely a result of her environment.

Another equally important aspect of Stargirl’s character is her great capacity to care for others, while at the same time refusing to let others hurt her. Stargirl is so full of compassion that she cheers for the opposite team at basketball games, comforts a wounded player on the opposing team, and runs out because she cannot stand to hear the crowd booing the opposition. She is always looking for nice things to do for other people—leaving surprise presents, singing Happy Birthday, and so on. However, when other students shun Stargirl, she appears impervious to their comments. Even when another student slaps her, Stargirl responds by kissing the student on the cheek. As Leo says, he has never seen Stargirl look in a mirror, never heard her complain—all of her emotions “flowed outward,” as if she were egoless. In a way, Stargirl’s behavior seems so remarkable, so free from human flaws, that she functions more like a symbol than a character. While other characters change in response to Stargirl, Stargirl herself remains the same. Even when she briefly changes her outer appearance to appear more normal, she still gives a Stargirl-like speech to win an oratory contest, and she soon shucks off her new appearance. Stargirl—and Leo, and the rest of the community—realize that someone as individualistic, as pure, and as true to herself as Stargirl is can never truly change who she is.

Archie Brubaker
Archie Brubaker, a minor but important character, is a paleontologist and retired professor who lives near the high school. Archie runs an informal, fun “school” about odd topics on Saturdays that is well-attended by the local youth, including Leo and Kevin. Archie also reveals to Leo and Kevin that while Stargirl was homeschooled over the past few years, Archie taught her once a week. Therefore, Archie has some insight into Stargirl’s character and seems as interested in her as Leo is. After Stargirl disappears, Leo goes to see Archie, and they ponder the mystery of Stargirl together; even after Leo grows up and moves away, he comes home to visit Archie and reminisce about Stargirl. Thus, Archie becomes the older, wiser, truth-telling voice in the narrative who illuminates the core of Stargirl’s character. As Archie tells Leo, he sees Stargirl as one of those rare people who is “a little closer to our beginnings, a little more in touch with the stuff we’re made of.” Through Archie’s words, we see Stargirl as a pure, hopeful soul with a strong connection to both the natural world and the world of humanity she cares for so deeply.