Organic-inorganic nanocomposite materials have attracted a great attention since they cover a wide range of properties by combining the contrasting properties and/or creating novel properties. Functional properties of composites could further be manipulated by stimuli such as light, pH, magnetic electric field, mechanical force, and heat. When the stimuli can control a wide range of materials' property, it can be applied to a device with an ON-OFF system: a switch. A switchable material should exhibit the property that is noticeably different upon stimulation (i.e. ON and OFF states) with reversible mechanism. Research on switchable materials has been actively carried out to maximize the difference between ON and OFF states by modifying the structure and composition of nanocomposites, and also on stimuli to control the response time. Switchable materials find their applications in various fields such as catalysts, sensors, photodetectors, memory devices, and drug delivery systems. In this review, we discuss the recent advances in the design/synthesis of organic-inorganic nanoscale materials in which their properties can be controlled in response to a specific stimulus. In addition, we introduce various stimuli (furthermore, multi-stimuli), applications of switchable nanocomposites in a wide range of fields, and also challenges with an outlook. (C) 2018 Elsevier Ltd. All rights reserved.