Monitoring, measuring, and controlling electronic systems in space exploration, automotive industries, downhole oil and gas industries, marine environment, geothermal power plants, etc., require materials and processes that can withstand harsh environments. Such harshness can come from the surrounding temperature, varying pressure, intense radiation, reactive chemicals, humidity, salinity, or a combination of any of these conditions. Here, recent progress in the development of flexible and stretchable electronic devices for harsh-environment applications is reviewed. Studies are considered on how the selection of a specific material is critical for a particular application and how the selection of the material plays a critical role in sustained performance. Certain examples are presented for selected applications. Works on methods and designs for achieving flexibility and stretchability in devices designed for harsh environments are also investigated. Finally, studies on packaging techniques that enable deployment of conventional electronic devices in harsh-environment applications are considered, with a few examples described.