Introduction: This scoping review explores the association between young adults’ personal relationships and their physical and mental health. We reviewed studies that examined the nature and the quality of interaction in personal relationships and its effect on physical and mental health among young adults. We excluded studies conducted on the population with psychiatric conditions or who are differently abled. Methods: We used the following network databases to find relevant research: Google Scholar, SCOPUS, Web of Science, EBSCO, PubMed, ERIC, Science Direct and JSTOR from August 2021 to December 2021. We obtained 64 studies following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping review (PRISMA-ScR) guidelines. Results and Discussion: Thematic analysis of the selected studies indicates that personal relationships have the potency to either foster or hinder young adults’ physical and psychological functioning and well-being. Quality of relationships with family members such as parents, siblings, and extended family members are significantly associated with mental health and well-being Furthermore, studies showed that romantic relationship status and psychosocial characteristics within relationship contexts affect the mental health of young adults. In addition, our review showed that support from friendships, friendship features, and quality could support young adults’ self-esteem, mental health, and well-being. Although we find mixed results on personal relationships’ effect on physical health, few studies show that personal relationships affect cortisol levels, multiple areas of biological regulation, and women’s level of dysmenorrhea among young adults. The results justify the need to apply preventive intervention in the community to eliminate risk factors and enhance protective factors by imparting empirically validated knowledge, attitudes, and skills for relationships among young people. Investments in community-wide preventive interventions, interpersonal skill development agendas in counseling and psychotherapies, are recommended. Conclusion: The present review highlighted the underlying cultural influences on relationships and the necessity to promote relationship research in non-western cultures, given the underrepresentation of non-western cultures in research., we have highlighted the underlying cultural influences on relationships and the necessity to promote relationship research in non-western cultures, given the underrepresentation of non-western cultures in research.