Background and Objectives: Family meals favor adolescent dietary quality and mental health. The aim of this study was to explores the relationships between parental behavior during family meals, and the subjective diet-related quality of life (SDQOL) of Japanese adolescents. Methods and Study Design: Participants comprised 664 second-year junior high school students aged 13-14 years from Kumamoto Prefecture, Japan. Survey items included sex, age, family structure, parental behavior during mealtimes (frequency of warnings/listening to children), frequency of family meals (number of meals taken together), and SDQOL. Participants were divided into two groups (low and high) based on the median SDQOL score. Logistic regression analysis was performed to examine the relationships among parental behavior during meals, frequency of family meals, and SDQOL. The dependent variable was SDQOL; independent variables were parental mealtime behavior and family meal frequency. Results: The high-SDQOL group comprised 150 boys (45.3%) and 167 girls (51.1%). Compared to those who ate with family 0–5.5 times per week, those who did so 7–9.5 (OR: 2.56, 95% CI: [1.64-4.00]) or 11.5–14.0 (OR: 2.87, 95% CI: [1.83-4.50]) times per week had a better SDQOL. Those whose parents listened during meals on four or more days per week, compared with three days or less, had a better SDQOL (OR: 4.06, 95% CI: [2.76-5.98]). Conclusions: Eating together more than seven times a week and having parents listen to them during meals are associated with better adolescent SDQOL.