Integrated datasets linking traits, spatial distributions, environmental variables and phylogenies are essential for comparative research, but remain limited for many plant taxa, including those which are most threatened. Cactaceae are a morphologically and ecologically diverse succulent family that are iconic components of ecosystems across the Americas, and face high extinction risk. To support future comparative research, we present CactEcoDB (The Cactus Ecological Database), an Open Access dataset of curated spatial, ecological, trait, phylogenetic, and diversification data for over 1,000 cactus species. CactEcoDB includes species-level trait data, geographic occurrence records, environmental variables, range size estimates, speciation rates, and the largest time-calibrated phylogeny of cacti to date. By integrating these diverse data in a single platform, CactEcoDB enables analyses of trait evolution, trait–environment interactions, biogeography, climatic niche evolution, and macroevolutionary dynamics in one of the most celebrated and threatened plant families.