Keloids are dermal fibroproliferative skin disorders caused by abnormal wound healing, resulting in impaired skin function and aesthetic defects. Abnormal fibroblast proliferation and excessive collagen deposition are involved in keloid formation. This study investigated the role of fibroblast differentiation in keloid development. Single-cell and bulk RNA sequencing data of keloids were comprehensively analyzed, and 25 clinically relevant differentially expressed fibroblast-differentiation-related genes (DEFDRGs) were identified. Based on DEFDRGs, a keloid diagnostic classification system comprising three subtypes was constructed, indicating that DEFDRGs could serve as therapeutic targets. Additionally, multiple microarray datasets, protein sequencing data, and immunohistochemical analyses of key markers in clinical keloid samples were used for further verification. In conclusion, this study established a molecular classification of keloids based on fibroblast differentiation, contributing to the further understanding of keloid pathogenesis and providing new insights for diagnosis and treatment.