The lived experiences of sexual minority and gender diverse (SMGD) people in romantic relationships remain relatively understudied compared to their heterosexual and cisgender counterparts. Existing research has predominantly focused on cisgender gay or lesbian individuals, particularly those who identify as White, resulting in significant gaps in our understanding of diverse SMGD experiences. This volume pioneers an effort to address this gap by uniting interdisciplinary researchers to examine key aspects of SMGD individuals' lives and relationships across 12 countries. Specifically, this book focuses on the individual well-being, relational well-being, social support, and dyadic coping of SMGD people. The book's insightful findings are invaluable to researchers, practitioners, policymakers, and anyone striving for a more equitable global society.