Employee’s well-being and work-non-work interface refers to the core topics in occupational health psychology. The Job Demands-Resources (JD-R) model offers a useful framework on antecedents of desirable well-being outcomes. The current research aimed to investigate the role of flexibility and its components (i.e., predictability, adaptability, and orderliness) for employee’s general and work-related well-being in typical and daily behaviors. To investigate this research question, two online-studies with convenience samples of German-speaking employees were conducted. In Study 1 (N1=279) adaptability was positively related to and predicted the facilitation between life domains beyond age, gender and the 24 character strengths. In Study 2 (N2t = 188, N2d=105) these results were replicated and extended for work-life balance and thriving. Furthermore, the results of the diary part of the study suggested a positive role of adaptability in predicting daily job satisfaction and thriving. Employees who acted more adaptive than usual on a particular day reported higher job satisfaction and thriving on that day. The current study contributes to the literature on personal resources in the JD-R model. The results suggest flexibility, and especially its component adaptability, to be a personal resource in the JD-R model for some aspects of employee well-being, such as facilitation between life domains and thriving. We argue that including educational content on flexibility in programs for leaders and employees may result in higher employee well-being.