<p>Ecological networks have traditionally been studied as static systems. However, growing evidence reveals that these networks are highly dynamic, responding to natural and human-driven environmental change in ways that alter species interactions and influence the resilience of ecosystems. In this Review, we explore the emerging concept of rewiring, which refers to changes in the underlying structure of ecological networks as a result of species responses to variation in environmental conditions. Across natural environmental gradients and in response to anthropogenic change, consistent mechanisms drive rewiring and are increasingly recognized as being central to how ecosystems function under global change. Rewiring is a fundamental property of ecological networks and must be explicitly considered in descriptions of how biodiversity and ecosystem functioning can be maintained in a variable world.</p>