This study investigates the core issue of Fear of Missing Out in adolescents. FOMO is anxiety stemming from concerns about being uninformed or excluded, leading to concerns about social integration. This tendency often affects adolescents, a demographic that is highly engaged in social media, as they seek to maintain relationships with peers and follow real-time social changes. This study aims to ascertain the relationship between the need for affiliation, loneliness, and fear of missing out (FOMO) in adolescents using quantitative research methods. The study sample consisted of 349 adolescents selected using incidental sampling from a population of 1,996,825 adolescents in the Sidoarjo area. JASP was used for data analysis in this multiple linear regression investigation. This method compared adolescents' social media use, loneliness, and FOMO. A substantial relationship between the need for affiliation and loneliness associated with FOMO in adolescents was found with a p value of 0.001.