Introduction and objective Childhood asthma is a significant public health concern and the most common chronic disease in children, particularly affecting those under five. Maternal factors, including age at delivery, may influence asthma risk, as teenage mothers often face socioeconomic challenges that impact child health. This study examines the association between maternal age at delivery (teenage vs. adult mothers) and childhood asthma. Methods This historical cohort study used secondary data from the 2021 National Survey of Children's Health. Children aged zero to five were included, excluding those born to mothers over 45, children with congenital defects, and those with a maternal asthma history. Multiple logistic regression was used to estimate adjusted odds ratios (OR, 95% CI) for asthma. Results Among 48,379 children, 1,110 (2.29%) were born to teenage mothers (≤19 years). Asthma prevalence was higher in children of teenage mothers (9.01%) than adult mothers (4.28%) (p < 0.001). Before adjustment, children of teenage mothers had more than twice the odds of having asthma compared to those of adult mothers (OR 2.21, 95% CI 1.79-2.73). After adjustment, the odds remained significantly higher (OR 1.39, 95% CI 1.09-1.77). Conclusion Children of teenage mothers have increased odds of developing asthma. Future research should explore mediating factors, such as socioeconomic and environmental determinants, to clarify this association. These findings highlight the need for targeted healthcare policies, such as improved access to prenatal care, mental health support, and parental education programs, to support teenage mothers and mitigate early childhood health risks.