Narcissism is a multi-dimensional personality trait characterised by grandiosity, vanity, low empathy, and a desire for admiration. Previous research has suggested that social media sites are ideal platforms for people with narcissistic traits to satisfy a desire for attention. However, less is understood about the relationship between social media and vulnerable narcissism, characterised by vulnerability, insecurity, and oversensitivity. A total of 115 participants completed the Hypersensitive Narcissism Scale (HSNS) and questions relating to social media use. Exploratory and confirmatory factor analysis supported a two-factor model of vulnerable narcissism; oversensitivity and egocentrism. Results showed that greater oversensitivity was significantly associated with greater scores in all six aspects of social media use. Specifically, time spent on social media, frequency of posts, concerns about numbers of likes and comments, being overly sensitive about negative remarks, feelings of jealousy, and a greater difference in how they portray themselves on social media compared to real life. Egocentricity was significantly associated with less concern over negative remarks and a greater difference in how they portray themselves on social media compared to real life. These results suggest that vulnerable narcissism is not a unitary trait and that subfactors oversensitivity and egocentricity contribute differentially to aspects of social media use.