Osmoprotectants are categorized as osmolytes, also known as compatible solutes, considering that they are small organic molecules that share characteristics, like low molecular weight, neutral charge, and low toxicity, even at high concentrations in cells. They are identified in different chemical classes, including polyamines (e.g., putrescine, spermidine, spermine), sugars (e.g., sucrose, trehalose, raffinose), sugar alcohols (e.g., myo-inositols), betaines (e.g., glycine betaine), and amino acids (e.g., proline). In plants exposed to abiotic stresses (salinity/drought), osmoprotectants help cellular turgor preservation and drive the water uptake gradient. Some osmoprotectants shield plants from damage through chaperone-like activities, helping in the conservation of membrane structures and protein functions, or scavenging for reactive oxygen species (ROS) generated by the stresses. Therefore, it is advantageous to understand how plants respond to abiotic stresses by regulating the expression of osmoprotectant-related genes. This chapter presents data on plant osmoprotectants, including their regulating genes, associated pathways, and transcriptional regulations in plants under abiotic stresses. There is also an overview of their in silico mapping (model plants/crops) and their biotechnological potential as transgenes. Furthermore, these approaches are new perspectives for the analysis and introgression of these related genes into cultivated plant species, improving advances in plant breeding and crop production.