Leo Percepeid
As in the vast majority of Kerouac's work, the fictional characters of The Subterraneans are placeholders for the real people in the author's life. In this case, Percepeid is Kerouac himself. Like Kerouac, Percepeid drank heavily, wrote frantically, and listened to jazz passionately as did his Beat cohorts. He is without a stable job and though already in middle age, still lives with his mother. Though he is often emotionally distant, he falls for Mardou Fox when they meet in New York in 1953. He pursues her fervently. Initially she rejects him but slowly they grow closer. They soon live together, but the arrangement is marred with Percepeid's jealousy and anger. When she leaves him he is left distraught, realizing how much he cared for her. He then sits down to write the novella that would be The Subterraneans.
Mardou Fox
Mardou Fox is the character name of Alene Lee, a former lover of Kerouac. She is half Cherokee Native American and half African-American, ten years younger than Percepeid. Her race factors greatly into her character, as she and Kerouac engaged in their relationship when interracial couples were frowned upon, and in some places, outlawed. She frequents jazz bars in San Francisco. The novel follows her and Percepeid as though move in to live together before their relationship quickly disintegrates. She is revealed to be a tender and caring character, though mentally and emotionally unstable. She attends psychoanalysis regularly, and is portrayed to be on the constant verge of a mental breakdown. She leaves Percepeid to be with other lovers, deeply hurting him.
Leroy
Neal Cassady appears briefly in the novella as the character Leroy. Unlike On the Road and The Dharma Bums in which Cassady figured as a central character, his role in The Subterraneans is insubstantial.
Adam Moorad
The character of Allen Ginsberg, Keraouc reveals that the word "subterraneans" was "a name invented by Adam Moorad who is a poet and a friend of mine." Percepeid reminisces fondly over their friendship, dating back over a decade. He is an independent character who often floats in and out of the narrative. At the beginning of the novel, Mardou is interested in Adam though he rejects her.
Larry O'Hara
Larry O'Hara, the real life Jerry Newman, is with Percepeid when they see Mardou for the first time. After Percepeid returns to his apartment for a party, he is not featured further.
Frank Carmody
Carmody, actually William S. Burroughs, is a wily friend of Percepeid. He also enjoys drinking heavily and writings. He is friends with Mardou Fox as well.
Arial Lavalina
Though not normally a character in Kerouac's work, Gore Vidal makes a brief appearance as Ariel Lavalina. He is a successful writer, noted with jealously by some of the Beats.
Yuri Gligoric
Gligoric is the stand-in for Gregory Corso. A peripheral character, he is a drunkard poet and friend of Percepeid's.
Roger Beloit
Percepeid is introduced to Beloit early in the novella. Beloit was the real life Allen Eager, a saxophonist. The men later go listen to him play with famed jazz musician Charlie Parker.
Julien Alexander
Alexander, or Anton Rosenberg, figures into the beginning of the novel. He is a "junkie" who "takes junk whenever he can."
