University workers have been marginalized in efforts to establish well-being at work and well-being outside the workplace. To date, no studies analyzing well-being have distinguished between teaching and research academic staff (TRAS) from the service and administrative staff (SAS). The purpose of this paper is to contribute to the promotion of the well-being of university workers. Data were collected from a representative sample of workers (N = 565) at the University of Extremadura (Spain) and were analyzed using Structural Equation Modeling and multi-group analyses. The results show that well-being at work is distinct for the TRAS and the SAS in terms of engagement, professional efficacy, and cynicism. The results also indicate that well-being at work has effects on well-being outside the workplace and that these effects vary according to the professional activity of university staff. This paper discusses these differences as well as their practical implications and makes suggestions for future research.