<p>The increasing integration of digital technologies into everyday life has intensified engagement in various cyber behaviors, raising important questions about their relationship with individuals' well-being. This study examined the associations between online moral disengagement, problematic internet use (compulsive internet use), benign and toxic disinhibition, cyberaggression, and cybervictimization with both hedonic and eudaimonic well-being among emerging adults in the United Arab Emirates. Furthermore, it explores the moderating role of personality traits in these associations. Data were collected from 671 emerging adults (46.8% women) aged 18–29&#xa0;years (<i>M</i> = 22.56; <i>SD</i> = 3.04). Results showed that cybervictimization and cyberaggression exhibited the strongest negative association with both hedonic and eudaimonic well-being. In contrast, benign disinhibition and problematic internet use were positively associated with well-being, suggesting that some forms of online engagement may have adaptive functions. Personality traits further shaped these associations: agreeableness, conscientiousness, and neuroticism moderated the relationship between problematic internet use and benign disinhibition and well-being, while extraversion and openness to experience displayed more context-specific moderating roles. By comparison, toxic disinhibition and online moral disengagement showed broadly negative associations with well-being, independent of personality. These findings highlight the complex interplay between cyber behaviors, personality, and well-being in emerging adults. While certain online activities may foster positive outcomes, others appear consistently harmful regardless of individual differences. Understanding these dynamics is crucial for developing interventions and policies that promote healthier digital engagement and protect well-being in increasingly technology-driven contexts.</p>