Over the last few decades, management has witnessed a proliferation of research on mergers and acquisitions (M&As) and strategic alliances (SAs). Although both fields have been widely studied, the relationship between the two bodies of literature has not been sufficiently explored. Despite the enormous commonality between both phenomena in terms of the drivers behind them and of the critical success factors associated with the M&A and alliance process management, scholars from the two fields have rarely exchanged findings and insights, even though they may be highly relevant to each other. M&A and SA research remain mostly separated from each other, thus minimizing the ability for more mutually beneficial complementary and synergetic knowledge sharing effects. This chapter synthesizes and compares existing theoretical perspectives from the M&A and SA literatures and identifies opportunities for future research and knowledge cross fertilization between the two fields. Building upon previous review studies about M&A and SA literatures, the authors develop a comparative longitudinal review of both literatures published in top management journals over a 27-year period. For that purpose, the authors resort to machine learning algorithms to discover thematic patterns that may have gone unnoticed by using traditional review methods. By highlighting some of the shortcomings that limit the authors’ theoretical and practical understandings, they challenge scholars from both fields (M&A and SA) to go beyond what they think they know from compartmentalized received theory, and draw upon novel and meaningful ideas, concepts, and theoretical approaches from “the other side of the fence.” The authors believe that such a dialog will facilitate further theoretical exploration and empirical investigation of both phenomena and produce insights that will influence the practical management of M&A and SAs.