Tremendous progress has been made in the field of electrochemical energy storage devices that rely on potassium‐ions as charge carriers due to their abundant resources and excellent ion transport properties. Nevertheless, future practical developments not only count on advanced electrode materials with superior electrochemical performance, but also on competitive costs of electrodes for scalable production. In the past few decades, advanced carbon materials have attracted great interest due to their low cost, high selectivity, and structural suitability and have been widely investigated as functional materials for potassium‐ion storage. This article provides an up‐to‐date overview of this rapidly developing field, focusing on recent advanced and mechanistic understanding of carbon‐based electrode materials for potassium‐ion batteries. In addition, we also discuss recent achievements of dual‐ion batteries and conversion‐type K−X (X=O2, CO2, S, Se, I2) batteries towards potential practical applications as high‐voltage and high‐power devices, and summarize carbon‐based materials as the host for K‐metal protection and possible directions for the development of potassium energy‐related devices as well. Based on this, we bridge the gaps between various carbon‐based functional materials structure and the related potassium‐ion storage performance, especially provide guidance on carbon material design principles for next‐generation potassium‐ion storage devices.