Our ability to interact with those around us plays an important role in our relationships, mental well being and ability to successfully navigate the complex social society in which we live. Research in social cognitive neuroscience aims to understand the underlying neurobiology of our social behaviours and interactions with others. Myotonic dystrophy type 1 (DM1) is a genetically inherited neuromuscular disorder characterized by mytonia with systemic manifestations such as cardiac disease, respiratory insufficiency, ophthalmic complications, diabetes and frontal balding among others. Individuals with myotonic dystophy have been found to have widespread changes throughout the brain in both grey and white matter territories. They have been noted to experience difficulty with social cognitive function, and to more frequently display atypical personality traits leading to often unrecognized difficulties with everyday life. In this mini review we explore the anatomical basis of social cognition, current techniques for measuring and investigating this impairment including facial emotion recognition and theory of mind. We examine the evidence for general cognitive dysfunction, autism spectrum and personality disorders in DM1. Throughout the review we discuss neuroimaging highlights relevant to social cognition in DM1. Finally, we discuss practical implications relevant to managing people with myotonic dystrophy and highlight future research needs.