Today's challenging times highlight the need for workplaces to support employee wellbeing. Workplaces can offer a means to improve employee wellbeing and promote health initiatives. However, small and medium-sized enterprises (SMEs) are less likely than larger organizations to engage with workplace wellbeing initiatives or offer wellbeing provision. This study, conducted in an urban area in central England, explores SME engagement with local government workplace wellbeing provision, and barriers and facilitators to SME engagement, SME implementation of wellbeing provision, and employee uptake. A mixed-methods design was used. Quantitative data were collected via a survey of 103 SMEs and qualitative data from three focus groups with stakeholders involved in promoting SME engagement with wellbeing support (n = 9) and 16 in-depth interviews with SME representatives (n = 8) and employees (n = 8). Quantitative data were analyzed using the chi-squared, Fisher's exact and Mann-Whitney U tests, and multivariable logistic regression. Qualitative data were analyzed using framework analysis. Findings highlighted several interrelated factors acting as barriers and facilitators to SME engagement with wellbeing initiatives, SME-provided wellbeing provision, and employee uptake. The study provides valuable insights for policymakers, public health teams, and SME leaders on improving provision of and engagement with wellbeing programs. Trust, awareness, knowledge, and communication are highlighted as important prerequisites of optimal provision and engagement.