Voluntary sports clubs (VSCs) provide the primary opportunities for organized community sport in the UK and thus hold the responsibility for delivering on mega-event sports participation legacies. This study presents findings from open-ended questionnaires and interviews conducted in two phases (Phase 1—Spring, 2013; Phase 2—Summer, 2015) with representatives from a sample (n = 39) of VSCs to understand their ability to deliver on the participation legacy goals of London 2012 and the 2014 Commonwealth Games in Glasgow. Thematic analysis of the data outlined three themes where support for VSCs should be placed when planning future mega-events: building VSC capacity, retaining members in the long-term, and promoting general visibility of the VSC throughout the event. Bid teams who hope to use mega-events as catalysts for sports participation increases should direct funding and guidance toward VSCs to ensure they have the tools, knowledge, and capacity to deliver on national sports participation ambitions.