Abstract Room temperature phosphorescence (RTP) materials, featuring large Stokes shifts, high exciton utilization, long lifetime, and multicolor emission, have consequently attracted widespread attention across various fields. Carbon dots (CDs) have rapidly emerged as a burgeoning research hotspot in materials science, owing to their ease of synthesis, low toxicity, excellent biocompatibility, and outstanding optical properties. Recent studies have highlighted the crucial role of host–guest strategies in both enhancing and precisely modulating the RTP performance of CDs, thereby expanding their potential applications across a wide range of fields. Despite significant progress, there remains a lack of comprehensive reviews that systematically elucidate the design strategies of CDs‐based host–guest materials and their correlation with RTP property modulation. This review addresses this gap by summarizing the latest advancements in CDs‐based host–guest RTP materials, with a particular focus on fundamental design strategies and mechanisms for performance modulation. On this basis, the potential applications of these materials in information security, intelligent optical devices, bioimaging, and optical sensing are discussed. Finally, in light of the current research landscape, the opportunities and future prospects for CDs‐based host–guest RTP materials are outlined, aiming to offer new insights for the advancement of this emerging field.