Background <p>Although several individual studies have examined how parental socioeconomic status (SES) relates to children’s sleep, current evidence remains fragmented and inconclusive—particularly for early childhood. This cross‑sectional study investigated the association between parental SES and preschool children’s sleep using household income and maternal educational attainment as indicators.</p> Methods <p>A questionnaire was administered in 2021 to parents whose children were 13–14&#xa0;years old and in the first year of middle school (<i>N</i> = 1,288). Overall, 652 valid responses were returned. To determine the association between parental SES and children’s sleep habits, children diagnosed with developmental disabilities and who did not respond to the required items on the questionnaire were excluded from the analysis. Thus, 528 (81.0%) children met the eligibility criteria. The relationship between SES and children’s sleep quality was analyzed using one-way analysis of variance (ANOVA) and multiple regression.</p> Results <p>We found that the lower the annual income and mother’s education level, the lower the children’s sleep quality. Thus, low family SES was associated with children’s subjective and objective sleep problems, shorter sleep duration, and worse subjective and objective sleep health. Conversely, children of parents with higher levels of education and income had a lower prevalence of sleep disorders.</p> Conclusions <p>This study suggests that parental SES is related to the quality of children’s sleep habits. Promoting regular sleep routines, ensuring appropriate assessment and treatment of sleep disorders, and fostering greater attention to sleep health during childhood may help mitigate SES‑related disparities in sleep outcomes.</p>