A growing number of educators and organizations using Open Educational Resources (OER) around the world have created training models to support educators on how to use and implement OER. Training ranges from webinars, online classrooms, and face-to-face workshops to equip individuals on OER use and promote its adoption. While this approach may be necessary, it is wrought with concerns and challenges. For example, training can be expensive, and the quality of training can be questionable when there is no oversight or standards regarding the question of quality and when the material is not correctly updated. Since training has been shown as essential to the adoption process, it is necessary to look at how this process is achieved. This article explores the use of the Training of Trainers Model (ToT) model, which is used in various disciplines to drive adoption. Using a systematic literature review (SLR) that provides real-life experiments on how the model has been implemented, the article makes the case that the ToT model must be implemented across institutions to drive the diffusion of OER. The contribution of this research is to guide how to implement the ToT model, particularly in higher education, to educators, administrators, librarians, and OER scholars interested in training others.