Assertiveness is a vital interpersonal skill that plays a significant role in the personal, academic, and professional development of young adults. It enables individuals to communicate their thoughts, feelings, and needs clearly and confidently, while respecting the perspectives of others. During the transition to adulthood, the ability to be assertive becomes increasingly essential as young individuals navigate complex social relationships and take on greater responsibilities. This study explores the relationship between family support, self-mastery, and assertiveness among young adults. It investigates how a supportive family environment and a sense of personal control (self-mastery) contribute to the development of assertive behavior. Assertiveness is not only linked to improved communication skills but also to enhanced academic performance, as it helps students express their concerns and engage more effectively with peers and educators. Drawing on existing literature, including the findings of Hurry et al. (2006), the study emphasizes the positive association between assertiveness and academic achievement. By examining the influence of psychosocial factors such as family support and self-mastery, the research aims to provide a deeper understanding of the predictors of assertiveness. The findings are expected to offer valuable insights for educators, parents, and counselors in fostering assertiveness among young adults, ultimately supporting their academic success and overall well-being