The evolution of e-commerce drives suppliers to develop online direct selling channels to encroach on the retail market, in addition to the traditional distribution channels through the retailer. A systematic literature review (SLR) approach is adopted in this paper to review the existing studies using theoretical models to capture supplier encroachment behavior, as well as the related industry practice phenomena and strategic factors in the supply chain. We present the major research streams according to the selected encroachment literature from two aspects: channel conflict and coordination as well as information structures. We also generalize the significant practical strategies and strategic factors that have been investigated, combined with supplier encroachment, such as investment and spillover effects, the retailer’s store brand introduction, strategic inventory, and contract mechanism designs. More importantly, we summarize the classical theoretical models which include the basic models, the signaling game model, and the Hotelling model, and these have been widely used by scholars to capture the supplier’s encroachment behavior. Finally, we provide several suggestions which may be valuable for researchers to identify future potential research directions.