This article reviews evidence for the social compensation hypothesis of online dating, according to which individuals who experience challenges with traditional dating gravitate towards and benefit from online dating. Three categories of psychosocial vulnerabilities that interfere with the initiation of romantic relationships are identified: 1) internalizing symptoms (i.e., anxiety, depression); 2) rejection sensitivity; and 3) attachment insecurity (i.e., anxiety, avoidance). The literature shows positive associations between anxiety, depression, rejection sensitivity, and attachment anxiety (but not avoidance) and online dating use. But significant lacunae exist in understanding the relational and wellbeing outcomes experienced by individuals with these psychosocial vulnerabilities, or of the mechanism through which vulnerabilities cause enhanced use of online dating. A detailed agenda for future research is proposed.