Background: the purpose of this study was to explore the effect of 10 weeks of yoga intervention on the mental health outcomes (stress, anxiety, and depression), quality of life, emotional regulation, and quality of sleep of medical students. Method: In the current experimental study, 220 medical students, with a mean age of 21.36 ± 2.20 years, participated in a 10-week yoga intervention at the University of Pécs. Data were collected before and after the intervention using the validated questionnaires DASS-21, WHOQOL-BREF, PSQI, and DERS. The distribution of data was checked using the Kolmogorov–Smirnov test. A paired sample T-test was used to compare the mean of the continuous variable. Stepwise linear regression was used to assess the association between mental health outcomes and quality-of-life variables. Results: The present study shows a significant reduction in (p < 0.001), depression (p < 0.001), and anxiety (p < 0.001) for participants, and overall quality of life (p < 0.001), quality of sleep (p < 0.001), and emotional regulation (p < 0.001) significantly improved after the intervention. The stepwise linear regression shows a strong association between higher levels of anxiety (β = 0.608, R² = 0.366) and depression (β = 0.608, R² = 0.392), with higher stress levels and improvement in environmental conditions being associated with a decrease in stress levels (β = −0.392, R² = 0.087). Conclusions: the current study shows that yoga significantly improved the mental health and well-being of medical students, improving quality of life, quality of sleep, and emotional regulation. Registered Clinical Trial: NCT06661603.