Due to its impact on mental health and well-being, fear of happiness is beginning to receive more attention in research. This study, conducted in Hungary, explored the relationship between fear of happiness, perfectionism, loneliness, hopelessness, and academic burnout. Participants aged between 18 and 35 years (N = 1,148, M = 22 years, SD = 4.5) completed an online questionnaire that included self-report measures of these constructs. In the present study, males showed higher levels of fear of happiness and perfectionism than did females. Analyses also revealed that both adaptive and maladaptive perfectionism, academic burnout, loneliness, and hopelessness were positively related to fear of happiness. In multiple regression analysis, gender had a positive and age had a negative role in the levels of fear of happiness. Maladaptive perfectionism, academic burnout, loneliness, and hopelessness were positive predictors, while adaptive perfectionism almost reached statistical significance. These findings highlight the predictive role of previously unexplored variables in fear of happiness.