Social media is ubiquitous among today's adolescents. With constant access, social media use can become dysregulated or problematic. Concepts, such as fear of missing out (FOMO), point to the negative effects of social media use. FOMO is a pervading unease that others are having rewarding experiences from which one is absent. For adolescents, meaningful experiences with peers are imperative for psychosocial development. Hence, adolescents could benefit from learning to regulate their social media use and how to access these platforms with intentionality. The current study focused on examining the effectiveness of a mindfulness- based intervention to address problematic social media use and FOMO among high school students (N = 54). The researcher used a quasi-experiment pretest-posttest design to examine the research question: Is there a difference in problematic social medial use, FOMO, mindful attention, and life satisfaction among adolescents that complete a MBI for social media compared to those who do not participate in the intervention? The author selected a repeated-measures ANOVA between-subjects statistical analysis to examine the differences between the pre and posttest data of the treatment and control groups. The results indicated a statistically significant difference between the intervention and control groups in PSMU and mindful attention. Yet, there was not a statistically significant difference between the groups' levels of FOMO and life satisfaction. The author includes a discussion of the results and implications for counselors, as well as the limitations and directions for future research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]