Meeting the complex demands of conservation requires a multi-skilled workforce operating in a sector that is respected and supported. Although professionalization of conservation is widely seen as desirable, there is no consistent understanding of what that entails. Here, we review whether and how eight elements of professionalization observed in other sectors are applicable to conservation: (1) a defined and respected occupation; (2) official recognition; (3) knowledge, learning, competences and standards; (4) paid employment; (5) codes of conduct and ethics; (6) individual commitment; (7) organizational capacity; and (8) professional associations. Despite significant achievements in many of these areas, overall progress is patchy, and conventional concepts of professionalization are not always a good fit for conservation. Reasons for this include the multidisciplinary nature of conservation work, the disproportionate influence of elite groups on the development and direction of the profession, and under-representation of field practitioners and of Indigenous peoples and local communities with professional-equivalent skills. We propose a more inclusive approach to professionalization that reflects the full range of practitioners in the sector and the need for increased recognition in countries and regions of high biodiversity. We offer a new definition that characterizes conservation professionals as practitioners who act as essential links between conservation action and conservation knowledge and policy, and provide seven recommendations for building a more effective, inclusive and representative profession.