ABSTRACTForage legumes have the unique attributes of producing a high‐quality forage to enhance animal performance and the ability to utilize atmospheric N that eliminates the legume plants dependence on soil N. Biological N2 fixation (BNF) rates are dependent on the infection by an effective rhizobia strain on the root hairs for each legume species. Producers planting forage legumes have the potential to utilize both benefits. However, both forage quality and BNF are influenced by numerous factors, including legume species, management practices, and climate, which determine their contribution to a forage‐livestock system. Because of soil and climatic differences, the region of the United States dictates which legume species are grown, how productive they are, and how they are utilized in a forage‐livestock system. Major factors influencing the contribution of legumes will be reviewed followed by a discussion of predominant legume species and their utilization in various regions of the United States.