Understanding how the world's flora and fauna will respond to bioenergy expansion is critical. This issue is particularly pronounced considering bioenergy's potential role as a driver of land-use change, the variety of production crops being considered and currently used for biomass, and the diversity of ecosystems that can potentially supply land for bioenergy across the planet. We conducted a global meta-analysis to ask how eight of the most commonly used bioenergy crops may impact site-level biodiversity. Species diversity and abundance were generally lower in crops being considered for bioenergy when compared to the natural ecosystems they may replace. First-generation crops, derived from oils, sugars, and starches, tended to have greater effects than second-generation crops, derived from lignocellulose, woody crops, or residues. Crop yield had non-linear effects on abundance and, to a lesser extent overall biodiversity, with biodiversity effects being driven by negative yield effects for birds but not other taxa. Our results emphasize that replacing natural ecosystems with bioenergy crops across the planet will largely be detrimental for biodiversity, with first generation and high yielding crops having the strongest negative effects. We argue that meeting energy goals with bioenergy using existing marginal lands or via biomass extraction within existing production landscapes may provide more biodiversity friendly alternatives than via land conversion of natural ecosystems. Impact Statement: Meta-analysis reveals that replacing natural ecosystems with bioenergy crops across the planet will largely be detrimental for biodiversity. This article is protected by copyright. All rights reserved.