This cross-sectional study assessed the nutritional status and dietary quality of 1,527 Cambodian secondary school students, focusing on gender, school type, location, socio-economic status, and maternal education. Data on demographics, BMI, and dietary intakes were collected, and dietary quality was evaluated using the Dietary Quality Index-International (DQI-I). Significant gender differences were found, with boys being older (16.80 ± 1.48 years vs. 16.38 ± 1.47 years, p<0.001), taller (167.83 ± 8.32 cm vs. 158.09 ± 6.10 cm, p<0.001), heavier (57.51 ± 12.55 kg vs. 49.19 ± 8.58 kg, p<0.001), and having higher BMI (20.365 ± 4.056 kg/m² vs. 19.66 ± 3.15 kg/m², p<0.001). Urban students exhibited higher dietary quality indices in variety, adequacy, and overall DQI (all p<0.01) compared to rural students. Private school students had better BMI and DQI score than public school students, with significant differences in height, weight, variety, adequacy, and overall DQI (all p<0.05). Socio-economic status significantly affected weight, BMI, variety, moderation, and overall DQI (all p<0.05). Higher maternal education levels were associated with improved dietary variety, adequacy, and overall DQI (all p<0.001). These findings underscore the need for targeted nutritional interventions and policies to address socio-economic disparities and improve educational opportunities for women, enhancing health outcomes for Cambodian students.