["Journal of School Health, Volume 96, Issue 8, August 2026. ", "\nABSTRACT\n\nBackground\nSleep difficulties are common in childhood and affect behavior, emotional regulation, and school functioning, yet are often unrecognized by caregivers.\n\nMethods\nThis population‐based, repeated cross‐sectional study included 1168 first‐grade children (6–7 years) in Évora, Portugal. Sleep was assessed using the Portuguese Children's Sleep Habits Questionnaire (CSHQ‐PT) and a structured family questionnaire. Associations with sociodemographic and family factors were examined using multivariable logistic regression; short sleep duration was analyzed using penalized logistic regression.\n\nResults\nAcross cohorts, 46%–49% of children met the criterion for clinically significant sleep disturbance (SDI ≥ 48). Bedtime resistance, daytime sleepiness, and sleep‐related anxiety were the most prevalent difficulties. Fewer than 10% of caregivers reported sleep problems, even among affected children. Clinically significant sleep disturbance was associated with caregiver education and later dinner timing, while longer commuting distance was associated with short sleep duration.\n\nImplications for School Health Policy, Practice, and Equity\nFindings support brief sleep screening and family‐oriented sleep health guidance at school entry.\n\nConclusion\nMany children begin primary school with unrecognized sleep difficulties, highlighting the value of integrating sleep health into early school health frameworks.\n"]