<![CDATA[Bullying is a serious problem that remains prevalent in educational settings, including Islamic boarding schools. The complex dynamics of life in these schools can give rise to bullying in various forms, where the role of bystanders is often overlooked. This study aims to examine the relationship between bystander bullying and self-esteem among students in Islamic boarding schools. The study employs a quantitative approach using a cross-sectional survey. The sample consisted of 448 middle school students (SMP/MTs/equivalent) from Islamic boarding schools in the Banyuwangi region, selected through purposive sampling. The instruments used were the Self-Liking Competence Scale-Revised (SLC-R) and the Student Bystander Behavior Scale (SBSS). Data analysis was conducted using descriptive statistics, normality tests, linearity tests, and Spearman’s rank correlation. The results indicate a significant and strong relationship between bystander bullying and self-esteem (r = 0.759; p = 0.000). Students who act as passive observers or supporters of bullying tend to have lower self-esteem, while those who actively defend victims demonstrate higher self-esteem. These findings emphasize the importance of strengthening the role of bystanders (bystander bullying) through interventions based on pesantren values to prevent bullying and improve psychological well-being. ABSTRAK Bullying merupakan permasalahan serius yang masih banyak ditemukan di lingkungan pendidikan, termasuk di pondok pesantren. Kompleksitas dinamika kehidupan di pesantren dapat memunculkan perilaku bullying dalam berbagai bentuk, di mana peran bystander (pengamat) sering kali luput dari perhatian. Penelitian ini bertujuan untuk mengetahui hubungan antara bystander bullying dengan self esteem santri di pondok pesantren. Penelitian menggunakan pendekatan kuantitatif dengan desain cross-sectional. Partisipan penelitian berjumlah 448 santri tingkat menengah Pertama (SMP/MTs/sederajat) di pondok pesantren wilayah Banyuwangi yang dipilih melalui teknik purposive sampling. Instrumen yang digunakan adalah Self-Liking Competence Scale Recides (SLC-R) dan Student Bystander Behavior Scale (SBSS). Analisis data dilakukan dengan menggunakan statistik deskriptif, uji normalitas, uji linearitas, dan uji korelasi Spearman Rank. Hasil penelitian menunjukkan adanya hubungan yang signifikan dan kuat antara bystander bullying dan self esteem (r = 0,759; p = 0,000). Santri yang berperan sebagai pengamat pasif atau pendukung bullying cenderung memiliki tingkat harga diri yang lebih rendah, sementara santri yang berperan aktif membela korban menunjukkan harga diri yang lebih tinggi. Temuan ini menekankan pentingnya penguatan peran pengamat (bystander bullying) melalui intervensi berbasis nilai-nilai pesantren guna mencegah bullying dan meningkatkan kesejahteraan psikologis santri. ]]>
