The narrator is a young middle-class Catholic schoolboy driven by a strong desire for wanderlust. He seeks an escape from the routine of his daily life and standard schoolyard games by planning a secret daytime excursion across Dublin. Though eager for adventure, he is highly observant and somewhat timid, preferring to watch rather than actively instigate trouble.

Mahony is an energetic Catholic schoolboy who accompanies the narrator on a journey across Dublin. He is highly active and prone to mischief, regularly using his catapult to chase stray cats and harass other children. He serves as a contrast to the more contemplative narrator, approaching their outing with brash confidence.

The Old Man is a shabbily dressed stranger who encounters the truant boys during their wandering. He initially speaks to them about literature and romantic sweethearts before excusing himself to engage in an unspecified act nearby. When he returns, his conversation shifts to a disturbing obsession with physical punishment.

Leo is a student known among his peers as an idler with a puffy face. He agrees to skip school and journey to the Pigeon House with his classmates but ultimately fails to appear at the meeting spot. His initial capture by a teacher sets the boys' desire for a real adventure into motion.

Joe is Leo's older brother and the ringleader of the local boys' afternoon games. He plays with an intensity that occasionally frightens the younger children. Despite his aggressive play style, it is widely believed that he will eventually join the priesthood.

Father Butler is an authoritative teacher at the boys' school. His strict reprimand of Leo effectively ruins the appeal of the boys' imaginary Wild West games. He represents the rigid religious and educational system that the boys seek to escape.

Mrs. Dillon is the mother of Joe and Leo. She is characterized primarily by her devout religious practices. She attends mass every morning, representing the deep-seated Catholic routines of the Dublin middle class.