This thesis examines the use of actor-based Applied Theatre methods within the workplace. Typically such methods are employed for behavioural skills training with the intention of enabling staff to effectively perform their work roles in a context of rapid and fundamental change to work practices and structures. This research uses case studies and mixed methods and finds that whilst work-based Applied Theatre may be commissioned for reasons of efficiency, in practice there is also the potential for individual efficacy. Whilst competitive forces drive the imperative for increased efficiency, the practice opens a space where the human consequences of this pressure can be explored. Studies of Applied Theatre have ignored or excluded the workplace as a site of research and consequently applications of these methods are under researched and little understood. This thesis questions the exclusive assumptions of the academic field, presenting a more complex picture of the practice than currently appears in the literature. Whilst the workplace presents many tensions that must be negotiated, this research finds that the participative, embodied and dialogic qualities of the practice can enable a space for catharsis, negotiation, expression and learning not possible through other methods. These dialogic and participatory qualities are found to promote a social model of leadership and interaction that is progressive, facilitating a shift away from pervasive mechanistic command and control approaches to management and leadership. A central quality of this efficacy and impact was found to be the role of the workplace actor which has evolved beyond the delivery of performance and into innovative approaches that aim to increase the actor’s contribution to learning. This emerging hybrid role is defined here as the ‘pedagogical actor’, drawing on skills of calibration, feedback and facilitation in addition to delivering a credible performance. Case Studies include an examination of the use actor-based role-play within financial services company Friends Provident and Forum Theatre used by the multi-national 3M, in addition to numerous case examples.