Introduction: Hearing loss is an important public health issue that negatively affects children’s speech, cognitive development, academic performance, and social interaction. Even mild hearing impairment may lead to adverse developmental outcomes. However, data on hearing loss among primary school children in Mongolia remain limited. Goals: To determine the prevalence, type, and severity of hearing loss among primary school students in Ulaanbaatar and to assess associated socio-demographic factors. Material and Method: A school-based cross-sectional study was conducted among 1,254 primary school students. Hearing screening was performed using pure-tone audiometry following a standardized protocol. Students who failed the screening were referred for confirmatory diagnostic audiometry. Hearing loss was classified as mild (21–35 dB), moderate (36–50 dB), and severe (≥50 dB). Socio-demographic data were collected using a structured questionnaire. Statistical analysis data were analyzed using RStudio software. Descriptive statistics were used to summarize participant characteristics. Associations between hearing loss and independent variables were examined using chi-square tests and logistic regression analysis. Variables with p<0.20 in univariate analysis were included in the multivariable logistic regression model. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported, and p<0.05 was considered statistically significant. Ethical considerations: The study protocol was approved by the Institutional Ethics Committee (Approval No. 2024/3 06). Written informed consent was obtained from parents or legal guardians, and assent was obtained from participating students prior to data collection. Results: Of the 1,254 students, 116 (9.2%) required further evaluation, and hearing loss was confirmed in 23 students (1.8%). Most cases were mild in severity. Paternal education level was significantly associated with hearing loss (p=0.028), whereas no significant associations were observed for sex or household income. Conclusion The prevalence of hearing loss among primary school students in Ulaanbaatar was 1.8%, with most cases being mild and unilateral. These findings highlight the importance of implementing regular school-based hearing screening programs and improving parental awareness of children’s hearing health.