Integrating proactivity and creativity literatures, we argue that people can perform more creatively at work when they proactively manage their levels of vitality. Proactive vitality management is defined as individual, goal‐oriented behavior aimed at managing physical and mental energy to promote optimal functioning at work. We hypothesize that this process may be facilitated by being aware of one's own state and by support from others. A total of 242 employees participated in a weekly diary study for three consecutive weeks, yielding 610 observations. Results of multilevel analyses show that participants reported more creative work performance during weeks in which they had proactively used vitality management. In addition, in line with our predictions, self‐insight and social support for creativity in the workplace acted as cross‐level moderators and strengthened the relationship between proactive vitality management and creativity. We conclude that a proactive approach regarding physical and mental energy is an important bottom‐up strategy that may foster creativity in work settings.