Abiotic stresses, such as extreme temperatures, drought, salinity, and other environmental adversities, significantly impact global food security by affecting crop yields. Crop wild relatives (CWRs) are plant taxa closely related to crops and serve as a valuable source of genetic diversity, which can help adapt crops to various abiotic stresses, particularly to meet the growing consumer demand amid the climate crisis. The historical evidence suggests that CWRs have been integral to crop improvement with successful examples in cereals, pulses, oilseeds, and other crops. Recent advances in genomics, including trait mapping and genome editing techniques, have successfully facilitated the identification and transfer of crucial traits from CWRs into modern crop varieties. Nevertheless, challenges such as the conservation of CWRs and the genetic complexities of integrating wild traits into cultivated varieties continue to be critical considerations in breeding programs. However, future direction toward an interdisciplinary approach combining advanced omic tools with effective strategies to ensure sustainable utilization of CWRs is an essential strategy to develop abiotic stress-resilient varieties. This chapter highlights the role of CWRs in enhancing abiotic stress tolerance, focusing on drought, salinity, and extreme temperatures in cereals, oilseeds, and pulses. It covers their genetic diversity, historical contributions, and potential in modern agriculture, along with advancements in genomics and breeding techniques. Challenges and future directions for utilizing CWRs are also discussed.