The extracellular matrix (ECM) plays a central role in directing dermal fibroblast behavior and coordinating tissue regeneration through its structural organization and biochemical signaling. In this study, we investigate the composition and regenerative bioactivity of Skin ECM in the context of dermal remodeling as a soluble supplement and surface coating for fibroblast culture. Proteomic profiling demonstrates that Skin ECM preserves the molecular complexity and skin-specific composition of native dermal ECM, including key structural and signaling proteins essential for tissue repair, with over 95% overlap with the human skin proteome, highlighting its strong tissue specificity and biological relevance. Functionally, Skin ECM enhances fibroblast migration during wound healing, upregulates elastin expression, and suppresses transforming growth factor beta 1 (TGF-β1)-induced expression of profibrotic and inflammatory markers, indicating inhibition of fibroblast activation. In vivo subcutaneous implantation confirms high local and systemic biocompatibility without signs of inflammation or toxicity. Collectively, these findings establish Skin ECM as a bioactive, tissue-specific, and immunologically compatible ECM material, offering broad utility in regenerative medicine, three-dimensional (3D) skin model systems, and dermal therapeutics including cosmetic interventions.