Biostimulants potentially improve crop growth, yield, and food production through efficient nutrient utilization and support of existing plant defense mechanisms under biotic and abiotic stress conditions. These substances also known as “plant conditioners” or “bioeffectors” offer a simplified and practical approach for addressing challenges posed by climate change through the ever-changing environmental conditions. Currently, applications involving biostimulants for agricultural sustainability have increased in nearly every dimension, bolstering crops’ resilience and increased performance of the plant’s vital morphological, physiological, and reproductive processes, achieving high and good quality yields. Biostimulants have been applied to crops enhancing nutritional efficiency regardless of the genotype and cultivation methods. Therefore, this chapter evaluated the role of biostimulants in improving crop growth, development, and response under abiotic stresses such as drought, extreme temperatures and salinity by examining the various raw materials in their compositions like proteins, humic acids, microbial extracts, algal extracts, and plant-based products explored for adaptation and mitigation, including food security. Subsequently, the contribution of biostimulants in improving the quality of crops produced for human consumption and their impact on the environment are also discussed and some preliminary conclusion drawn regarding their overall application and safety regulations.