ABSTRACT Digital technological development and the increasing use of social media among adolescents have brought both positive and negative impacts, one of which is the rising incidence of cyberbullying that affects victims’ psychological conditions. This study focuses on the forms of self-defense mechanisms used by adolescent victims of cyberbullying at SMA Negeri 12 Banjarmasin in dealing with psychological pressure resulting from such experiences. This research employs a qualitative approach with a descriptive design. The research subjects were selected using purposive sampling, consisting of two student victims of cyberbullying, a Guidance and Counseling teacher, and the Vice Principal. Data were collected through in-depth interviews, observation, and documentation. The data were analyzed using the Miles and Huberman model, which includes data reduction, data display, and conclusion drawing, and validated through source and technique triangulation. The results indicate that victims employ nine forms of defense mechanisms, namely denial, projection, reaction formation, displacement, fixation, regression, repression, rationalization, and sublimation. The most dominant mechanism is reaction formation, reflected in the tendency of victims to remain friendly, calm, and positive despite experiencing emotional distress. The study concludes that defense mechanisms not only serve to reduce anxiety but also function as adaptive strategies for adolescents in maintaining social relationships and gaining environmental acceptance. ABSTRAK Perkembangan teknologi digital dan meningkatnya penggunaan media sosial di kalangan remaja telah membawa dampak positif sekaligus negatif, salah satunya adalah meningkatnya kasus cyberbullying yang berdampak pada kondisi psikologis korban. Penelitian ini berfokus pada bentuk-bentuk mekanisme pertahanan diri (self-defense mechanisms) yang digunakan remaja korban cyberbullying di SMA Negeri 12 Banjarmasin dalam menghadapi tekanan psikologis akibat pengalaman tersebut. Penelitian ini menggunakan pendekatan kualitatif dengan jenis deskriptif. Subjek penelitian ditentukan melalui teknik purposive sampling yang terdiri dari dua siswa korban cyberbullying, guru Bimbingan dan Konseling, serta Wakil Kepala Sekolah. Data dikumpulkan melalui wawancara mendalam, observasi, dan dokumentasi. Kemudian dianalisis menggunakan model Miles dan Huberman yang meliputi reduksi data, penyajian data, dan penarikan kesimpulan, serta diuji keabsahannya melalui triangulasi sumber dan teknik. Hasil penelitian menunjukkan bahwa korban menggunakan sembilan bentuk mekanisme pertahanan diri, yaitu denial, proyeksi, reaction formation, displacement, fiksasi, regresi, represi, rasionalisasi, dan sublimasi. Mekanisme yang paling dominan adalah reaction formation, yang ditunjukkan melalui sikap tetap ramah, tenang, dan positif meskipun mengalami tekanan emosional. Simpulan penelitian ini menunjukkan bahwa mekanisme pertahanan diri tidak hanya berfungsi sebagai cara mengurangi kecemasan, tetapi juga sebagai strategi adaptif remaja dalam mempertahankan hubungan sosial dan memperoleh penerimaan lingkungan.