Background: Workplace wellbeing has become a key focus of occupational and public health, with increasing attention to mental health, psychosocial risks, fatigue, and work–life balance. However, limited evidence compares employee and employer perspectives, distinguishes support availability from support use, or examines whether wellbeing is more closely associated with isolated interventions or the broader support environment. Method: Cross-sectional survey data were collected from public-sector employees (N = 1307) and employers (N = 321) in Ontario, Canada. Analyses compared employee and employer ratings of workplace wellbeing dimensions and supports, examined support availability and use, and assessed associations between support use and perceived workplace impact on personal wellbeing using linear regression models. Results: Employees consistently rated workplace wellbeing dimensions and supports as more important and more effective than employers. Several supports were widely available, but availability varied across sectors and did not consistently translate into use, particularly for mental health, psychological health and safety, and fatigue-related supports. Among employees using at least one support, the cumulative number of supports used was positively associated with wellbeing (B = 0.196, p < 0.01), whereas few individual supports demonstrated independent associations. Fatigue management programs showed a consistent positive association across model specifications. Conclusions: Findings suggest that workplace wellbeing is associated with the broader support environment, not only with individual programs. Employee-informed, integrated approaches that improve both access and uptake may strengthen workplace wellbeing; however, causal interpretation is limited by the cross-sectional design.