Proactive behaviors are defined as employees’ future-oriented, agentic behaviors that aim to improve workplace conditions. Recent research alludes that employee perceptions of whether they have permission to act proactively may influence their actions. With these ideas in mind, this dissertation introduces the concept of proactivity permission, which is defined as the perception of the extent to which an employee is allowed to perform proactive actions at work. Using a multilevel research design with 501 employees from 112 work groups, I examined the effects of employee and supervisor personality characteristics, relational factors, and contextual factors on proactivity permission. Findings indicate that employee personality characteristics (i.e., psychological entitlement and psychological reactance) positively influence employee proactivity permission beliefs, whereas supervisor personality characteristics (i.e., social dominance orientation and rule-based reasoning) negatively influence proactivity permission judgments of supervisors. The quality of relationships (LMX) between a focal employee and his/her supervisor positively affects both employee proactivity permission and supervisor proactivity permission judgments, while workplace contextual factors (e.g., organizational rule formalization, rule consistency, and normative tightness) are relatively distal to, and play a minor role in, proactivity permission. Additionally, this dissertation finds that employees who believe they have permission to act proactively engage in proactive behaviors to a greater extent, and that supervisors are more supportive toward the proactive behaviors of those employees who they perceive to have greater permission to act proactively. In all, this dissertation offers important contributions to theory and research on employee proactivity and suggests several practical recommendations for managers and organizations who are interested in fostering greater proactivity in the workplace. / Business Administration/Human Resource Management