ABSTRACT Motivated by the increasing use of online games among adolescents, which has the potential to cause addiction and aggressive behavior, this study examines the relationship between self-control and online game addiction with aggressive behavior among vocational high school students in Nogosari District. This quantitative study used a survey method involving 83 students of SMK Negeri 1 Nogosari who were randomly selected from a total population of 490 students. Data were collected through self-control scales, online game addiction scales, and aggressive behavior scales, all of which had been tested for validity (Aiken's V) and reliability (Cronbach's Alpha). Multiple linear regression analysis using SPSS 26, after meeting classical assumption tests, was conducted to assess the simultaneous and partial relationships among the research variables. The results showed that self-control and online game addiction simultaneously had a significant relationship with aggressive behavior. Partially, self-control had a negative and significant effect on aggressive behavior (?: -1.019, <0.000), whereas online game addiction had a positive and significant effect (?: 0.284, <0.05). These two variables explained 46% of the variability in aggressive behavior, with the remaining influenced by other factors. These findings emphasize the role of self-control as a protective factor and online game addiction as a trigger for aggressive behavior, highlighting the importance of psychological and educational interventions in schools and families to enhance self-control and manage online game use among adolescents. ABSTRAK Dilatarbelakangi oleh peningkatan penggunaan game online di kalangan remaja yang berpotensi menimbulkan kecanduan dan perilaku agresif, penelitian ini menguji hubungan antara kontrol diri dan kecanduan game online dengan perilaku agresif pada siswa SMK di Kecamatan Nogosari. Studi kuantitatif ini menggunakan metode survei pada 83 siswa SMK Negeri 1 Nogosari yang dipilih secara acak dari total populasi 490 siswa. Data dikumpulkan melalui skala kontrol diri, kecanduan game online, dan perilaku agresif, yang telah diuji validitas (Aiken's V) dan reliabilitas (Alpha Cronbach). Analisis regresi linear berganda dengan SPSS 26, setelah memenuhi uji asumsi klasik, dilakukan untuk menilai hubungan simultan dan parsial antara variabel penelitian. Hasil penelitian menunjukkan bahwa kontrol diri dan kecanduan game online secara simultan berhubungan signifikan dengan perilaku agresif. Secara parsial, kontrol diri berpengaruh negatif dan signifikan terhadap perilaku agresif (?: -1.019, <0.000), sementara kecanduan game online berpengaruh positif dan signifikan (?: 0,284, <0,05). Kedua variabel ini menjelaskan 46% variabilitas perilaku agresif, dengan sisanya dipengaruhi faktor lain. Temuan ini menekankan peran kontrol diri sebagai pelindung dan kecanduan game online sebagai pemicu perilaku agresif, menggarisbawahi pentingnya intervensi psikologis dan edukatif di sekolah dan keluarga untuk meningkatkan kontrol diri dan mengelola penggunaan game online pada remaja.