Anthropogenic activities (including flow management, channelisation, and land-use encroachment) have constricted river networks, separating main channels from riparian zones and floodplains. The restricted lateral migration of a river changes the flow, sediment dynamics, and diversity of geomorphic units in the system, with extensive ecological consequences including habitat simplification and biodiversity loss. In the face of climate change and the increasing occurrence of flood and drought extremes, awareness is growing around the importance of giving rivers room to move. However, protecting human infrastructure tends to be the focus of management and policy, often without considering the resilience of ecosystems. Here, we reviewed the literature and revealed five categories of ecological effects that can emerge or strengthen as a result of allowing lateral channel migration on river floodplains: 1) habitat heterogeneity and patch diversity; 2) a mosaic of asynchronous connectivity; 3) a mosaic of asynchronous disturbance; 4) a terrestrial-aquatic nexus; and 5) balanced biological, geological and hydrological drivers of channel morphology. The ecological features and processes within these categories interact to support species diversity and community stability, thus improving ecosystem resilience. Highlighting these consequences within the context of river management and identifying future research opportunities have the potential to influence process-driven freshwater conservation and restoration at the landscape scale.