This study aimed to investigate the relationship between teachers' emotional intelligence and the mental health of first-year elementary school students in Ardabil city in the academic year 1404-1405. The research method was applied in terms of purpose and descriptive-correlation in terms of data collection method. The statistical population of the study included all teachers working in the first-year elementary school in Ardabil city, which was reported to be 389 people according to education statistics. Using the stratified random sampling method and based on the Cochran formula, 193 people were selected as the research sample. The data collection tools included the emotional intelligence questionnaire of Schott et al. (1998) and the general mental health questionnaire (GHQ-28). The collected data were analyzed using SPSS software version 27. In the descriptive statistics section, the mean, standard deviation, and frequency indices were used, and in the inferential statistics section, the Kolmogorov-Smirnov test was used to examine the normality of the data distribution, and the Pearson correlation coefficient and multivariate regression analysis were used to test the research hypotheses. The results of the study showed that there is a positive and significant relationship between teachers' emotional intelligence and students' mental health. The results of the regression analysis also showed that teachers' emotional intelligence can explain a significant part of the variance in students' mental health. These findings indicate that teachers who have a higher level of emotional intelligence can play an effective role in reducing anxiety, stress, and psychological problems of students by creating positive emotional interactions, better understanding students' emotional needs, and appropriate management of emotions.