The term ‘mentoring’ is used for a wide range of contexts but this chapter will be limited to the consideration of mentoring in pre-service teacher training and early career teaching, as in both of these areas there is good evidence that a more capable teacher who provides professional or emotional support to another can support professional development and significantly reduce attrition (e.g. Nguyen 2017; Hobson and Malderez 2013). Initially, three facets of mentoring will be examined (emotional support, technical support and support with reflection) and the tensions between them. The second part of the chapter goes on to consider ways in which mentor training can be effected. Mentors may see this role as part of their own reflective growth (Orland-Barak and Rachamim 2009) and use the experience for personal reflection, to contribute to the profession or to prevent personal burnout, but it is also true that they often have this responsibility thrust upon them with little or no preparation. An illustration of an approach to mentor training where the fundamental elements are experiential learning, scaffolded with online and face to face input and supported by reflection between peers and with a mentor-tutor will be presented.