Introduction – Nutrition knowledge is crucial for athletes' performance and health, yet data on Hungarian athletes are limited. Methods – This study assessed sport nutrition knowledge and its influencing factors among 1, 335 athletes (132 elite, 1, 203 recreational; 54.3% male; mean age = 22.74 ± 8.11 years) using the Hungarian Abridged Nutrition for Sport Knowledge Questionnaire (ANSKQ-HU) alongside sociodemographic, sport-related, and perception-based variables. Analyses included Kruskal–Wallis H-tests, Mann–Whitney U-tests, MANCOVA and Kendall's tau correlations. Results – Overall, 63.37% of athletes scored in the poor nutrition knowledge category (< 50%). No significant differences were observed by gender, sport level or prior nutrition education. Education level significantly affected sports nutrition knowledge, with higher-educated participants showing better fundamental and overall understanding than those with primary education. These findings were independent of training frequency and age, with medium post hoc effect sizes (d = 0.31 – 0.35). Weekly training hours and age were weakly correlated with FEP (fundamentals of nutrition, energy requirements of physical activity, and prohibited substances) subscale (p < 0.01) and total scores (p < 0.01). Participants valuing healthy eating scored higher on FEP (χ² = 30.840, p < 0.001, η² = 0.022) and total ANSKQ-HU (χ² = 22.612, p < 0.001, η² = 0.015). Access to both nutrition information and dietitian support improved MPE (micronutrients and performance-enhancing sports nutrition) (U = 71, 395, Z = 3.28, p = 0.001) and UM (utilization of macronutrients) scores (U = 68, 231, Z = 3.75, p < 0.001). Discussion – Our findings highlight the need for structured nutrition education and dietitian access in sports organizations. Importantly, as the data were collected exclusively from Hungarian athletes, these results reflect country-specific characteristics and should be interpreted within the Hungarian sport and educational context.