Introduction: Depression is a growing concern among medical students, exacerbated by the demanding curriculum and academic pressures. Students from vernacular-medium schooling background may face additional challenges due to language barriers when transitioning to an English-medium medical education. This study aims to assess the prevalence and severity of depression among first-year medical students who completed their schooling in Vernacular medium and explore the impact of language barriers on their mental health. Materials and Methods: A cross-sectional observational study was conducted among 150 first-year medical students from a medical college in South India, all of whom had completed their schooling in Vernacular medium. Sociodemographic data were collected using a pre-designed proforma, and the Patient Health Questionnaire-9 (PHQ-9) was used to assess depression. Students with a prior history of mental illness or chronic conditions were excluded from the study. Descriptive statistics and Chi-square analysis were applied to evaluate the prevalence and gender differences in depression severity. Results: The study revealed that 65.33% of the students experienced depression. Among them, 31.3% had mild, 24% moderate, 8.7% moderately severe, and 1.3% severe depression. Female students were more likely to suffer from depression than male students, with a significant gender difference observed (p-value < 0.05). Most of the students (68%) belonged to lower middle-class families, and 76% were from rural areas. Discussion: The high prevalence of depression among Vernacular-medium students highlights the significant role of language barriers in mental health outcomes. Students transitioning from Vernacular to an English-medium medical curriculum face difficulties in understanding academic content, contributing to their mental health challenges. Female students and those from lower socioeconomic backgrounds are particularly vulnerable. Conclusion: This study underscores the need for targeted mental health interventions, including language support and counselling services, to reduce depression among Vernacular-medium medical students.