Polymers are widely used in optical devices, electronic devices, energy‐harvesting/storage devices, and sensors, owing to their low weight, excellent flexibility, and simple fabrication process. With advancements in micro/nanoprocessing techniques and more demanding application requirements, it is becoming necessary to realize high‐resolution fabrication of polymers to prepare miniaturized devices. This is particularly because conventional processing technologies suffer from high thermal stress and strong adhesion/friction, which can irreversibly damage the micro/nanostructures of miniaturized devices. In addition, although the use of advanced fabrication methods to prepare high‐resolution micro/nanostructures is explored, these methods are limited to laboratory research or small‐batch production. This review focuses on the micro/nanoprocessing of polymeric materials and devices with high spatial precision and replication accuracy for industrial applications. Specifically, the current state‐of‐the‐art techniques and future trends for micro/nanomolding, high‐energy beam processing, and micro/nanomachining are discussed. Moreover, an overview of the fabrication and applications of various polymer‐based elements and devices such as microlenses, biosensors, and transistors is provided. These techniques are expected to be widely applied for multiscale and multimaterial processing as well as for multifunction integration in next‐generation integrated devices, such as photoelectric, smart, and biodegradable devices.