A review of recent advances in flexible printed gas sensors is presented. During the last years, flexible electronics has started to offer new opportunities in terms of sensors features and their possible application fields. The advent of this technology has made sensors low-cost, thin, with a large sensing area, lightweight, wearable, flexible, and transparent. Such new characteristics have led to the development of new gas sensor devices. The paper makes some statistical remarks about the research and market of the sensors and makes a shot of the printing technologies, the flexible organic substrates, the functional materials, and the target gases related to the specific application areas. The conclusion is a short notice on perspectives in the field.