BACKGROUND: Keloid formation is characterized by excessive production of extracellular matrix, leading to dysregulated fibroproliferative collagen response. N6- methyl-adenosine (m6A) modification plays an essential role in this process. OBJECTIVE: Our objective in this study was to explore the mechanism of m6A methyltransferase KIAA1429 in keloid formation. METHODS: We examined the impact of m6A methyltransferase KIAA1429 on keloid formation using qRT-PCR, Western blot, immunofluorescence, Transwell migration assay, and MeRIP-qPCR. RESULTS: KIAA1429 was downregulated in keloid tissue. Overexpression of KIAA1429 suppressed fibroblast migration and reduced COL1A1 and α-SMA levels. Conversely, the knockdown of KIAA1429 promoted fibroblast migration and COL1A1 and α-SMA levels. Additionally, overexpression of KIAA1429 inhibited the TGF-β1/Smad pathway. Mechanistic experiments suggested that KIAA1429 regulated TGF-β1 m6A modification, maintained TGF-β1 mRNA stability, and participated in the regulation of keloid formation. Furthermore, TGF-β1 could reverse the effects of KIAA1429 overexpression on fibroblast migration and collagen deposition. CONCLUSION: Taken together, our study suggested that KIAA1429 promoted keloid formation through the TGF-β1/Smad pathway, providing new insights for the treatment of keloid.