UAVs are valuable sources of data for inspection, surveillance, mapping, and 3D modeling. They offer a low-cost alternative to traditional manned aerial photogrammetry, enabling new applications in short- and close-range domains. UAVs can operate in manual, semi-automated, and autonomous modes, and can be equipped with amateur or SLR digital cameras. Following a typical photogrammetric workflow, 3D results such as digital surface models, terrain models, contours, textured 3D models, and vector information can be produced, even on large areas. This paper reviews the state of the art of UAVs for geomatics applications, providing an overview of different UAV platforms, applications, and case studies, as well as the latest developments in UAV image processing. It also addresses new perspectives. UAVs are defined as aircraft without a human pilot onboard. They are often referred to as drones, remotely piloted vehicles, or other terms based on their propulsion system, altitude, endurance, and level of automation. The term "unmanned aerial system" includes the UAV and the ground control station. UAVs were initially developed for military purposes, but have since become common in geomatics for data acquisition. UAV photogrammetry opens new applications in close-range aerial domains, offering a low-cost alternative to traditional manned aerial photogrammetry for large-scale topographic mapping and detailed 3D recording of ground information. UAVs are a valid complementary solution to terrestrial acquisitions. UAV platforms include fixed and rotary wings, with various launch methods. The cost of a typical UAV platform for geomatics purposes ranges from 1,000 to 50,000 Euros, depending on onboard instrumentation, payload, flight autonomy, and automation level. Low-cost solutions often require human assistance for take-off and landing. More stable systems, generally based on internal combustion engines, have longer endurance and can carry medium format cameras or LiDAR/SAR instruments. Hardware and platform developments are driven by robotics, aeronautical, and optical communities to miniaturize optical systems, enhance payload, achieve autonomous navigation, and improve flying performance. UAVs are categorized into tactical and strategic systems based on size, weight, endurance, range, and flying altitude.UAVs are valuable sources of data for inspection, surveillance, mapping, and 3D modeling. They offer a low-cost alternative to traditional manned aerial photogrammetry, enabling new applications in short- and close-range domains. UAVs can operate in manual, semi-automated, and autonomous modes, and can be equipped with amateur or SLR digital cameras. Following a typical photogrammetric workflow, 3D results such as digital surface models, terrain models, contours, textured 3D models, and vector information can be produced, even on large areas. This paper reviews the state of the art of UAVs for geomatics applications, providing an overview of different UAV platforms, applications, and case studies, as well as the latest developments in UAV image processing. It also addresses new perspectives. UAVs are defined as aircraft without a human pilot onboard. They are often referred to as drones, remotely piloted vehicles, or other terms based on their propulsion system, altitude, endurance, and level of automation. The term "unmanned aerial system" includes the UAV and the ground control station. UAVs were initially developed for military purposes, but have since become common in geomatics for data acquisition. UAV photogrammetry opens new applications in close-range aerial domains, offering a low-cost alternative to traditional manned aerial photogrammetry for large-scale topographic mapping and detailed 3D recording of ground information. UAVs are a valid complementary solution to terrestrial acquisitions. UAV platforms include fixed and rotary wings, with various launch methods. The cost of a typical UAV platform for geomatics purposes ranges from 1,000 to 50,000 Euros, depending on onboard instrumentation, payload, flight autonomy, and automation level. Low-cost solutions often require human assistance for take-off and landing. More stable systems, generally based on internal combustion engines, have longer endurance and can carry medium format cameras or LiDAR/SAR instruments. Hardware and platform developments are driven by robotics, aeronautical, and optical communities to miniaturize optical systems, enhance payload, achieve autonomous navigation, and improve flying performance. UAVs are categorized into tactical and strategic systems based on size, weight, endurance, range, and flying altitude.