In many fields of civil engineering, the needs for innovative sensing technologies are growing. Ground-penetrating radar (GPR) is actually one of the most advanced sensing technologies available, allowing a nonintrusive inspection of the materials under investigation. GPR uses radar pulses to image the subsurface, exploiting electromagnetic (EM) radiation and then detecting the reflected signals from subsurface structures. This chapter provides an overview of GPR sensing technologies for civil engineering applications and related research topics. In particular, a number of promising concepts for GPR are introduced and discussed in this chapter, starting from the theoretical EM background of GPR signal propagation in soils and construction materials. Then, we illustrate the applications of GPR to civil engineering fields, from the construction and inspection of transportation infrastructures and hydraulic works, to geotechnical surveys, environmental monitoring, as well as building and bridge structural assessments. We will demonstrate why GPR is currently considered as one of the most effective and efficient sensing technologies and is a potential candidate to become the best available remote-sensing technology for civil engineering applications. Finally, a wide literature review will be presented in order to give the reader all of the sources of information useful for any in-depth study.