Research conducted to date has identified a knowledge gap associated with understanding the beliefs of parents who have not enrolled their children in formal swimming lessons 1. The current research aims to address this gap, investigating the beliefs of these parents, and using a rigorous mixed methods approach to predict parents’ intentions to enrol their children into formal swimming lessons outside of school. This study was conducted in two phases. Phase 1 (N = 22) was an elicitation study which employed qualitative methods to elicit the salient beliefs that parents of children never enrolled in formal swimming lessons held towards enrolling their children in formal swimming lessons (i.e., a registered swimming lessons program conducted outside of school education) for the first time. Building on the results of Phase 1, Phase 2 (N = 323) employed quantitative methods to examine the key beliefs and social cognition factors impacting upon the intentions of parents of non-enrolled children to enrol their children in formal swim lessons in the next six months. Data from Phase 1 were analysed using content analyses, and data from Phase 2 were analysed using multiple regression and structural equation modelling. Results identified a range of key beliefs that predicted intentions of parents to enrol their child in formal swimming lessons, including the belief that enrolling their child would help to keep their child safe in the water, that the enrolment would be approved of by the child’s other parent and their friends, and that they were not inhibited from enrolling their child due to cost or lack of time. Results further indicated that of the social cognition factors from the theory of planned behaviour—attitudes, subjective norms, and perceived behavioural control—parents’ intentions to enrol their child were predicted by subjective norms and perceived behavioural control, but not attitudes. Of the additional factors included as part of the integrated model that was tested—role construction, risk perceptions, and autonomous motivation—intentions to enrol were predicted by role construction and risk perceptions. Although autonomous motivation did not have a direct predictive effect on intentions, there was an indirect effect of autonomous motivation on intentions through the theory of planned behaviour variables. This study has important implications for the uptake of formal swimming lessons and, thus, prevention of drowning deaths among young people and adults. Specifically, the study shows that modifiable psychological factors predict parents’ intentions to enrol their child in swimming lessons in the next 6 months.