Purpose: The purpose of this paper is to bring together job design and career theory in the examination of how proactive employees optimize their well-being (i.e. job satisfaction and perceived health) through job crafting and career competencies. This study offers an integrated account of the pathway from proactive personality to well-being. Design/methodology/approach: Data were collected by a cross-sectional self-report survey study among 574 employees working in various organizations. Findings: The results of structural equation modeling analyses supported the proposed double mediation model: job crafting and career competencies both mediated the positive relationship between proactive personality and well-being. The findings suggest that proactive employees can enhance their well-being both through proactive job redesign and the development of career-related skills and abilities. Research limitations/implications: This study precludes causal explanations. Future research should further investigate the role of employee proactivity related to contemporary work topics, including temporary contracts and self-employment. Practical implications: Managers and HR practitioners can optimize employee well-being by focusing on HR policies related to job redesign, as well as investing in training and development of career competencies. Originality/value: This paper integrates two research domains by exploring how proactive employees take a proactive stance toward their job as well as their career, and investigates how this proactive approach contributes to their well-being. In addition, the authors demonstrated a link between the development of career competencies and employee health.