Background: Outdoor walking groups are widely-used programmes aimed at improving physical activity and health outcomes. Despite being promoted as accessible and inclusive, emerging work highlights participation biases based on gender, age and socioeconomic status, for example. To explicate the impact of outdoor walking groups on physical activity inequities, we conducted a scoping review of published outdoor walking group literatures. Specifically, we critically examined: (a) equity integration strategies; (b) intervention reach; (c) effectiveness; and (d) potential social determinants of engagement relating to the World Health Organization's conceptual framework. Methods: Arksey and O'Malley's scoping review protocol was used to develop a comprehensive search strategy and identify relevant academic and grey literatures, which were screened using pre-defined inclusion and exclusion criteria. Data were organised by Cochrane PROGRESS-Plus equity characteristics and a narrative summary was presented for each thematic area. Findings: Sixty-two publications were included. Key findings were: (a) some evidence of targeted intervention trials. Large-scale national programmes were tailored to regional activity and health needs, which may contribute toward addressing inequities. However, participant demographics seldom informed reported analyses; (b) participation was more likely among white, more socioeconomically advantaged, middle-to-older aged, female and able-bodied adults; (c) positive physical and psychological outcomes were unlikely to extend along social gradients; and (d) interventions primarily addressed intermediary determinants (e.g. psychosocial barriers; material resource). Social capital (e.g. friend-making) was identified as potentially important for addressing physical activity inequalities.