Background: Fear of missing out is a pervasive apprehension that others might be having rewarding experiences from which one is absent. Aim: assess the relationship between personality traits, fear of missing out (FOMO), and depression among social media users. Design: A descriptive - correlational design. Setting: The study was conducted at Assiut and Qena city in Egypt utilizing web-based online. Sample: Included 385 social media users. Tools of the study included socio-demographic data, Ten-Item Personality Inventory-(TIPI), Fear of Missing out Scale (FOMO), and the Depression scale (DEPS). Results: (13.20±9.041) of the studied persons who have depression were more than 11 hours using the net but (11.60±7.435) of them were more than 20 times using the net. Persons who have openness to experiences were positively and significantly correlated with times of using the net (r=.125*& p=.029). The FOMO is positively and significantly correlated with the depression scale, the FOMO is positively and non-significantly correlated with Extraversion and Openness to Experiences. Conclusion: extraverted individuals and persons who are open to experiences have positive relations with FOMO because they searching for new and they are afraid of missing any events via social media. Also, the person who spends much time using the internet and checks the internet more than one time per day is complaining of depression. Recommendations: Implementation of psycho-educational programs for social media users to teach them how they can manage their leisure time rather than checking social media.

Keywords: Depression, Fear of missing out, Personality traits & Social media users.