Sports betting is growing exponentially, is heavily marketed and successfully targets young adult males. Associated gambling problems are increasing. Therefore, understanding risk factors for problem gambling amongst sports bettors is an increasingly important area of research to inform the appropriate design and targeting of public health and treatment interventions. This study aimed to identify demographic, behavioural and normative risk factors for gambling problems amongst sports bettors. An online survey of 639 Australian sports bettors using online, telephone and retail betting channels was conducted. Results indicated that vulnerable sports bettors for higher risk gambling are those who are young, male, single, educated, and employed full-time or a full-time student. Risk of problem gambling was also found to increase with greater frequency and expenditure on sports betting, greater diversity of gambling involvement, and with more impulsive responses to betting opportunities, including in-play live action betting. Normative influences from media advertising and from significant others were also associated with greater problem gambling risk. The results of this study can inform a suite of intervention, protection and treatment initiatives targeted especially at young male adults and adolescents that can help to limit the harm from this gambling form.