<![CDATA[Abstract The development of social media, particularly TikTok, has a significant influence on the fast fashion consumption behavior of Generation Z, which is associated with Fear of Missing Out (FoMO), defined as anxiety arising from feeling left behind in information or trends. This study aims to analyze the relationship between self-concept and peer pressure and FoMO among Generation Z fast fashion consumers who use TikTok in Surabaya. The study employed a quantitative correlational approach with 152 respondents selected through purposive sampling based on specific criteria and analyzed using multiple regression analysis. The results indicate that self-concept and peer pressure simultaneously have a significant relationship with FoMO (F = 109.270; p < 0.05). Partially, self-concept shows a significant negative relationship with FoMO (t = −3.911; p < 0.05), while peer pressure shows a significant positive relationship with FoMO (t = 6.761; p < 0.05). These findings emphasize the important role of self-concept and peer pressure in efforts to prevent FoMO among Generation Z TikTok users. Abstrak Perkembangan media sosial, khususnya TikTok, berpengaruh besar terhadap perilaku konsumsi fast fashion Generasi Z yang berkaitan dengan Fear of Missing Out (FoMO), yaitu kecemasan akibat merasa tertinggal informasi atau tren. Penelitian ini bertujuan menganalisis hubungan konsep diri dan peer pressure terhadap FoMO pada konsumen fast fashion Generasi Z pengguna TikTok di Surabaya. Penelitian menggunakan pendekatan kuantitatif korelasional dengan 152 responden yang dipilih melalui purposive sampling sesuai kriteria tertentu dan dianalisis menggunakan regresi berganda. Hasil menunjukkan bahwa konsep diri dan peer pressure secara simultan berhubungan signifikan dengan FoMO (F = 109,270; p < 0,05). Secara parsial, konsep diri berhubungan negatif signifikan dengan FoMO (t = −3,911; p < 0,05), sedangkan peer pressure berhubungan positif signifikan dengan FoMO (t = 6,761; p < 0,05). Temuan ini menegaskan pentingnya peran konsep diri dan peer pressure dalam upaya pencegahan FoMO pada Generasi Z pengguna TikTok.]]>
