There is a growing need to identify acceptable and feasible opportunities to engage adults over 35 years in physical activity. Walking sports may be a potential means to engage adults in sport; however, there is limited evidence regarding appeal and feasibility to support its implementation and delivery. Using a two-step mixed-methods approach, we aimed (1) to quantitively identify significant predictors of intentions of adults over 35 years to participate in walking sports and (2) to understand why and how these identified predictors may be contextually relevant to the target group. In phase one, 282 adults over 35 years (Mage = 46.08, SD = 9.75) without prior experience of walking sports completed an online questionnaire assessing personal, psychosocial, program-related, and environmental predictors, and intentions to participate in walking sports. Hierarchical multiple linear regressions showed that perceived health status, attitudes, subjective norms, and distance of venue were significant predictors of intentions. In phase two, interviews with a subset of 17 participants indicated that, when implementing walking sport programs, program labeling, fear of the unknown, and individual differences in the appeal of walking sport warrant consideration. Together, these findings offer insight into the complex interplay of personal, psychosocial, program-related, and environmental predictors of adults' intentions to participate in walking sports. Addressing these elements of a walking sport program would make such programs more appealing to potential participants, and ultimately, more feasible and sustainable to conduct in the long run. © 2023 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.