Legume crops are indispensable for global food security due to their high protein content and phytonutraceutical properties. Despite their importance, legume crops suffer from poor crop yields due to limited areas of cultivation, various biotic and abiotic stress factors, as well as poor agriculture infrastructure. The increasing global population as well as aggravating climate change has further worsened the situation. The recent revolution in genome sequencing and annotation has opened the gateway for legume crop improvement through advanced molecular breeding tools such as genomic selection, genetic engineering, and genome editing. Gene editing by CRISPR-Cas9 and its derivative systems is a powerful tool to make specific genetic changes at precise positions in the genome facilitating rapid crop improvement through precision breeding. In this chapter, an overview of the basic machinery of CRISPR-Cas9 and allied gene editing systems is provided followed by a comprehensive outline of the execution of a basic CRISPR-Cas9 gene editing experiment including various tools and techniques for construct designing and result analysis. The application of CRISPR-Cas9-mediated gene editing in several legume species is also discussed. We have also discussed the major constraints and bottlenecks faced during the practical implementation of genome editing techniques in legume crops.