Happiness is a core concept in people’s daily life. Understanding and facilitating the happiness, psychological well-being and its causative factors lies within the key issues in the realm of positive psychology. The present research purpose is to identify the factors influencing the happiness of students. Therefore, the sample comprised 364 students (F=183, M=181) who were selected using multi-stage random cluster sampling form among all the students studying in Islamic Azad University, Science and Research branch. The selected subjects were tested regarding happiness, personality characteristics, family environment, mental health, optimism and coping styles. Subsequent to the elimination of variables such as age, gender, education, number of siblings, problem-focused and avoidant coping mechanism, expressiveness, independence, achievement orientation, organizing and control which didn’t show any significant relationship with happiness, the stepwise regression analysis indicated that personality traits, emotion-focused coping strategy, being at ease with oneself and others, ability to meet the needs of mental health, cohesion, conflict, optimism, logical-cultured, active-uninhibited, moral-spiritual approaches explain 55 percent of the variance of happiness among the students.