The study of interpersonal relationships has been one of the areas of psychology with the most theoretical and scientific development. This field has been of interest to many psychologists from different fields, such as clinical, organizational, educational, and social, among others. As numerous investigations have indicated over the years, interpersonal relationships are one of the pillars of mental health. For this reason, studies from different perspectives are of great relevance in the advancement of knowledge about the psychology and mental health of humans. This book aims to contribute to this purpose, presenting conceptual and empirical advances on social skills and interpersonal relationships that arise from different practices and contexts that have been affected by COVID-19.