This chapter is intended to provide an introduction to geographic information system (GIS) and associated landscape tools and to illustrate the ways in which they are being used in various aspects of agronomy. GIS technology is bringing about rapid changes in the way that agronomic analysis and management are being conducted. GIS coupled with remote sensing, Global Positioning System (GPS), electronic sensors, and computer technologies is providing new methods for data acquisition, storage, processing, analysis, and modeling. These new tools allow us to quantitatively describe landscapes and processes. The chapter discusses site-specific farming (SSF)—that is, farm management based upon variable soil and microclimate conditions that occur within most fields. SSF reduces waste, because fertilizer and herbicide—for example—are applied only where needed. New and/or improved models need to be developed to fully take advantage of the spatial nature of the data provided by these tools. The development of these models will rely on spatial statistical analysis techniques to quantify the accuracy of input parameters and model output. Many new tools are being used in this rapidly evolving field of GIS. Three-dimensional scene simulation, visualization, and animation linked with remote sensing and image processing technologies, and real time data collection will be needed in the study of agronomic systems. The development and use of three-dimensional GIS and spatiotemporal GIS will be an increasingly important area of research. The agronomic community—including farmers, land managers, fellow scientists, policymakers, and the general public should benefit from this evolving and expanding field.