Objective: To determine the prevalence of soil-transmitted helminth (STH) infection and associated factors among ethnic minority primary schoolchildren in An Phu ward, Gia Lai province, in 2026. Methods: A cross-sectional study was conducted among 354 ethnic minority students in grades 1–5 at Le Lai Primary School. Stool specimens were examined using the Kato thick-smear technique. Demographic characteristics, household conditions, and hygiene behaviors were collected using a questionnaire. Data were analyzed in Stata 17.0; associations were expressed as odds ratios (ORs), 95% confidence intervals (CIs), and p values. Results: Twenty-six of 354 students (7.34%) had STH infection. Hookworm eggs were detected in all positive samples; no Ascaris lumbricoides or Trichuris trichiura eggs were detected. Prevalence was 15.22% among Bahnar students and 2.33% among J’Rai students (OR = 7.54; p < 0.001). In univariable analyses, infection was associated with a father’s education at primary level or below (OR = 4.25), eating raw vegetables (OR = 11.12), drinking unboiled water (OR = 4.75), not washing hands after defecation (OR = 4.58), and defecating on soil (OR = 2.84); all p values were < 0.05. Conclusion: The prevalence of STH infection was 7.34%, and hookworms were the only helminth group detected. Ethnicity, paternal education, and several hygiene behaviors were associated with infection in unadjusted analyses. The findings support culturally appropriate hygiene education and improved sanitation.