Introduction: Rates of sexually transmitted infections are high among young people, and there is a need for research on how to reduce sexual risk behaviours, particularly in the context of the digital age. We tested a model to determine the psychological mechanisms that convey risk for contracting sexually transmitted infections, including sexual communication, dating application use, impulsivity, alcohol use and attachment anxiety, with a view to improving interventions. Design and Methods: Over 1000 young people aged 18-25 participated in an online survey including measures of psychological mechanisms and sexual risk behaviours. They were recruited from university courses. The proposed model was tested using structural equation modelling. We tested whether alcohol use moderated the relationship between impulsivity and sexual communication, and whether dating application use moderates the relationship between low sexual communication and sexual risk taking such that this relationship is stronger for those using dating applications. Results: Findings indicated that the model provided a good fit to the data. Dating application use predicts risky-sexual behaviours; however, in contrast to predictions, higher efficacy predicted greater risk-taking. Alcohol use was related to sexual communication, but it did not moderate the relationship between impulsivity and sexual communication. Discussions and Conclusions: Findings indicate that interventions should address the role of dating application use on sexual health and communication. Further research is required to determine the precise relationship between communication self-efficacy and sexual behaviours. These findings advance our understanding of targets for prevention of sexual risk-taking among young people in the digital age. Disclosure of Interest Statement: LEA has received a Children's Hospital Foundation Top Up Scholarship and has been supported by a Research Training Program living allowance stipend from The University of Queensland. MJG is supported by a Medical Research Future Fund Translating Research into Practice Fellowship (1167986).