Grain legume crops are an important component of global food and nutritional security and help in maintaining agro-ecological systems. They fix atmospheric nitrogen via the root-inhabiting rhizobacteria, thereby minimising the harmful effects caused by the excessive application of synthetic nitrogenous fertilizers in the soil environment. There has been less focus on legume crop wild relatives for harnessing their potential traits and novel gene(s) to incorporate them into the cultivated legumes for developing climate-resilient grain legumes. In this edited book, we will highlight the importance of various potential traits of crop wild relatives, which are yet to be properly harnessed for designing future climate-resilient grain legumes. We also update how advances in molecular genetics and genomics have enabled the underpinning of several candidate genes/genomic regions in various crop wild relatives harbouring adaptive traits that confer climate resilience in grain legumes. Readers will benefit from new information on various crop wild relatives in grain legumes and how these wild relatives could be explored for novel climate resilience genes for developing future climate-resilient legume crops. They will gain an understanding of how genomic advances (genome sequence, pan genomes) have uncovered the novel genomic regions attributed to climate resilience in various grain legumes. Finally, the critical role of these wild relatives in maintaining the lost gene(s) due to the domestication process will be discussed. Comprehensive information on conventional breeding, advanced breeding, and recent advances in genomics covering all the major crop wild relatives of legumes is not available in a single book. Thus, this book will provide readers with the latest updates on various information covering all aspects of wild species of legumes.