||Land degradation affects an estimated 24% of the global land area. While predominantly discussed as an environmental problem, degraded lands have recently been reconsidered as an untapped resource for production industries like agriculture and forestry. Here, we investigate the biodiversity potential of degraded land compared to both used and undisturbed land. First, we find that “degraded lands” and related terms cover a wide variety of socio-ecological settings and that a standardized terminology is clearly needed. Second, degraded lands may support biodiversity levels similar to or even above those of surrounding managed landscapes. However, degraded lands generally support less biodiversity than natural areas. Third, some principles to harness degraded lands for biodiversity conservation have been developed. If applied, degraded areas may provide opportunities to extend nature conservation strategies on a broader spatial scale, and they may serve as a buffer between protected areas and intensively used land. We conclude that efforts to capitalize on degraded lands for commodity crop production generate conflicts with biodiversity conservation that have been disregarded so far.