Background: Population health literacy constitutes a comprehensive competency to access, understand, appraise, and apply health information, serving as a foundational prerequisite for disease prevention frameworks. Within primary healthcare settings, nursing counseling plays a pivotal role in fostering healthy behaviors among citizens; however, there remains a critical need to quantitatively evaluate the correlation between these behavioral modifications and health literacy, thereby establishing an evidence-based analysis. Aim: To assess the level of health literacy and healthy lifestyle habits among citizens, and to evaluate their correlation with nursing counseling and support. Materials and Methods: A cross-sectional analytic study was conducted between August and September 2026, enrolling 145 citizens aged 18 and older who received care at the Tsetsekhairkhan Family Health Center of Songinokhairkhan district, Ulaanbaatar city and Telmen Soum Health Center in Zavkhan Province. HL was evaluated using the Mongolian version of the HLS-EU-Q16 questionnaire, and total scores were calculated. Nursing involvement was evaluated via a structured questionnaire. Data analysis was performed using SPSS 21.0, utilizing logistic regression analysis to determine Odds Ratios (OR) and p-values. Results: The mean HLS-EU-Q16 score of the participants (n=145) was 10.4±3.2. Regarding HL level distribution, 42.1% (n=61) were inadequate, 34.5% (n=50) were problematic/limited, and 23.4% (n=34) possessed sufficient health literacy. Participants perceived nursing support as highly influential (58.8%) and moderately influential (29.8%) in adopting healthy habits. Regular recipients of health counseling from nurses demonstrated a 3.79-fold higher likelihood of actively pursuing a healthy lifestyle (OR=3.79, 95% CI: 1.84–7.81, p=0.001) and a 3.05-fold higher likelihood of implementing the counseling into practice (OR=3.05, 95% CI: 1.35–6.88, p=0.0076). Conclusion Although citizens exhibit a limited capacity to independently search for and appraise health information—reflecting an overall inadequate level of HL—nurse-led counseling and support exert a direct, statistically significant positive impact on enhancing healthy behaviors among citizens.