This study investigates the influence of fear of missing out (FoMO) on phubbing behavior among adolescent social media users in Indonesia. The research employs purposive sampling to select 158 teenage respondents who use social media. The phubbing behavior scale is based on communication disturbance and phone obsession, while the FoMO scale is based on self and relatedness. The study uses simple regression testing with SPSS version 25 for MacOS. The results indicate that the hypothesis is accepted with a significance value of 0.000 (p<0.05), suggesting that FoMO has a very significant effect on phubbing behavior in adolescent social media users. The study concludes that the fear of missing out significantly influences phubbing behavior, emphasizing the need for adolescents to manage their smartphone usage and for researchers to explore other variables affecting phubbing behavior.This study investigates the influence of fear of missing out (FoMO) on phubbing behavior among adolescent social media users in Indonesia. The research employs purposive sampling to select 158 teenage respondents who use social media. The phubbing behavior scale is based on communication disturbance and phone obsession, while the FoMO scale is based on self and relatedness. The study uses simple regression testing with SPSS version 25 for MacOS. The results indicate that the hypothesis is accepted with a significance value of 0.000 (p<0.05), suggesting that FoMO has a very significant effect on phubbing behavior in adolescent social media users. The study concludes that the fear of missing out significantly influences phubbing behavior, emphasizing the need for adolescents to manage their smartphone usage and for researchers to explore other variables affecting phubbing behavior.