This paper examines the extent to which attending major sporting events leads to subsequent changes in the sport participation behaviour of spectators. The research covered seven single-sport events of World or European level held in the UK in 2014 and was concerned with spectators (aged 16 and over) who attended one of these events. Baseline data was gathered from a sample of spectators at each event using a face-to-face survey. Follow-up data was captured using an online survey at least nine months post-event. Our analysis is based on 258 people for whom both baseline and follow-up data were available (matched pairs). Using the Transtheoretical Model (TTM), the evidence from this research points to a small (net) positive staged change in sport participation among the sample overall. Variations in the nature and scale of changes associated with events featuring different sports were observed. Progression between the TTM stages was evident for individuals who were previously in the pre-preparation, preparation and action stages. The likelihood of progression appears to be strongest where prior contemplation for behaviour change was prevalent. Event attendance emerged as an important contributor for moving individuals along the TTM continuum, alongside a range of other factors. The demonstration or trickle-down effect was the primary mechanism by which any sport participation legacy supported by these events occurred. The practical applications of the research and the wider health benefits of leveraging event-induced sport participation increases are discussed.