Large-scale sampling of stony coral species richness, species distribution, and cover was undertaken at 423 Florida Keys sites between Miami and SW of Key West during 2005 and 2007. A two-stage, stratified random sampling design employed belt transects to enumerate numbers of species and point-intercept surveys to quantify cover. The sampling design incorporated ten reef and hard-bottom habitats from < 1 m to 27 m depth, as well as oceanographic regions and areas inside and outside of protected management zones. These data provide insights into the spatial extent and factors influencing stony coral biodiversity. For stony corals, a pool of ~50 taxa encompassing the Orders Milleporina and Scleractinia, including species and morphotypes, was recorded. Significant differences were found in species richness and cover among cross-shelf habitats, with great values on inner shelf margin patch reefs, followed by deeper fore-reef slope habitats that extended to the 27 m depth limit sampled. In contrast, the shallow fore-reef, especially in areas historically dominated by the branching coral Acropora palmata, yielded relatively low numbers of species and cover that are presently dominated by smaller, brooding corals such as Porites astreoides and Favia fragum.