Land tenure security is increasingly recognized as a foundational element for advancing global sustainable development agendas, but questions remain about how it affects human well-being and environmental outcomes. We identify 117 studies that aimed to estimate the causal effect of land tenure security interventions on these outcomes. Approximately two-thirds of these studies reported positive links between improved tenure security and human well-being or environmental outcomes. Close to half of the studies that examined social and environmental outcomes reported positive impacts on both. The majority of studies assessed government-implemented interventions that statutorily recognized rights through land titling and formalization in the 1990s and 2000s. More research is needed to bolster the body of evidence on the effects of non-technical interventions (for example, capacity building and awareness raising) and the devolution of rights to inform future land policy efforts and accelerate sustainable development. A meta-analysis of 117 studies to determine the impacts of land tenure security on socio-environmental outcomes and sustainable development.