Technology acceptance has become one of the dominant research trends in the domain of learning management systems (LMSs). While a plethora of several research studies conducted in this area, there is still a scarcity of knowledge concerning a holistic review and taxonomy of studies in this field. Thus, the main objective of this systematic review is steered toward understanding the most prevalent theoretical models and the most prominent external factors affecting the LMS adoption in higher educational institutions. Out of 732 collected studies between 2005 and 2020, a total of 68 studies were critically reviewed and analyzed. The main results indicated that the TAM, DeLone and McLean IS success model, UTAUT, TRA, DOI, and UTAUT2 have been dominating the theoretical landscape in LMS research. The results also elucidated that external factors linked to LMS acceptance models fall primarily into three macro-categories, including individual variables, contextual variables, and psychological/behavioral constructs driven from other theories. It is believed that the results of this review can serve as a departure point for synthesizing more advanced hybrid adoption theoretical models on the one hand, and a standardized inventory of factors affecting the LMS adoption on the other hand. Several theoretical contributions, practical implications, and future research paths were discussed.