Oligosaccharides play a crucial role in enhancing plant defense mechanisms against various abiotic stresses, making them valuable in sustainable agriculture. These carbohydrate polymers, including fructooligosaccharides (FOSs), galactooligosaccharides (GOSs), and xylooligosaccharides (XOSs), possess unique structural and physicochemical properties that contribute to stress tolerance. Their biosynthesis and functional attributes enable plants to withstand adverse environmental conditions such as drought, salinity, temperature extremes, and heavy metal toxicity. The mechanisms by which oligosaccharides enhance stress tolerance include stress sensing, signal transduction, and the regulation of gene expression. They assist in scavenging reactive oxygen species (ROS), modulating hormonal pathways, and upregulating defense-related genes. Additionally, epigenetic modifications contribute to the plant’s adaptive response. Oligosaccharides help mitigate drought stress by improving osmotic balance and maintaining membrane integrity. Under salinity stress, they support ion homeostasis and activate stress tolerance pathways. Similarly, they contribute to temperature resilience by enhancing cold and heat stress responses, while also aiding in heavy metal detoxification through chelation and antioxidant system enhancement. The integration of oligosaccharides with modern breeding and genetic engineering offers promising advancements for developing stress-resilient crops. However, challenges remain, including gaps in research, scalability issues, and the need for further biotechnological innovations. Future research should focus on optimizing their application to enhance crop productivity and environmental sustainability. As oligosaccharides continue to gain attention, their potential to contribute to resilient agricultural systems highlights their importance in addressing global food security challenges.