Domestic livestock grazing accounts for roughly one quarter of the world's terrestrial surface and is a leading driver of biodiversity loss. Yet, it also provides a critical livelihood for nearly one billion smallholder farmers, creating a paradox that highlights the need for conservation strategies to balance human and ecological needs. Silvopastoral systems (SPS) integrate trees with livestock pastures, offering a promising solution to boost livestock productivity while safeguarding natural areas and biodiversity. However, evidence for the biodiversity benefits provided by SPS is limited to studies focusing on specific geographic regions or taxa. Through a global meta-analysis of 45 studies spanning 15 countries, four biogeographic regions, and seven taxa, we provide the first quantitative synthesis evaluating how SPS affect biodiversity and community stability relative to treeless pastures and natural forests. Overall, we show that SPS harbor higher levels of biodiversity (i.e., richness, abundance, and diversity) and stability than treeless pastures, and perform comparably to nearby forests. However, variations exist across regions and taxa, with the strongest positive responses in tropical dry regions and for low-mobility taxa like invertebrates and plants. Mammals, birds, and soil microorganisms, on the other hand, showed no significant biodiversity differences between treeless pastures and SPS. Thus, integrating SPS and protected areas as complementary components of a multifunctional landscape will be key to halting multi-taxa biodiversity loss and building sustainable livestock systems. Our findings support the conservation potential of SPS, while underscoring the need for strategic implementation to maximize benefits for biodiversity conservation.