This study examined the effects of interaction with others in vacation on subjective happiness and depression. Employees have been experiencing substantial changes in working conditions, and such changes cause an increase of stress. In such a background, the number of people with mental health disorder is rising, and it becomes a major problem in these days. Previous studies have indicated that vacation greatly influences on individual subjective happiness and stress state. However, the number and area of participants in previous studies were limited. Therefore, we conducted an Internet survey and collected participants of various ages from different areas in Japan. The total of 275 adults (109 women, 166 men) participated in this study. As a result of the analysis, the interaction with others in vacation was positively associated with subjective happiness, whereas subjective happiness was negatively associated with depression symptoms as a reaction to stress. These results suggest that reconsidering about vacation have a possibility to promote individuals’ mental health.