All living things depend on water, a precious natural resource, to survive. One of the biggest problems facing the energy, industrial, and agricultural sectors is the timely availability of water. Population development, industrialization, and urbanization all contribute to an increase in the demand for water, necessitating a deep comprehension of hydrologic processes and the spatiotemporal variability of water resources. Studies on hydrologic and water resource management have shown great potential in this respect for the application of geospatial methods in conjunction with hydrological models. Hydrologic models developed to model the behavior of watersheds are classified into eight categories: lumped, distributed, semi-distributed, conceptual, physical, empirical, deterministic, and stochastic. These categories are based on the degree of sophistication and complexity of the models. To enhance performance, geospatial techniques are also used into semi-distributed and distributed models. In this chapter, the application of geospatial techniques to hydrological modeling is covered in detail.