Acid-Solubilized Collagen (ASC) and Pepsin-Solubilized Collagen (PSC) were extracted from the mantle of the common European squid, and were comparatively characterized. ASC and PSC were isolated with an extraction yield of 5.1 and 24.2% (on dry weight basis), respectively. SDS-PAGE showed that the ASC was mostly comprised of α1- and α2-chains; while the PSC presented relevant β- and γ-components. GPC analysis confirmed that both the ASC and the PSC consisted of fractions characterized by different molecular weight. Thermal denaturation behavior of ASC and PSC were followed by calorimetric and rheological analyses; denaturation temperature was estimated to be 22°C for ASC and 21°C for PSC. Amino acid composition and solubility of collagen were also investigated. Finally, the cytotoxicity of the isolated collagen was evaluated in vitro and no cytotoxic activity caused by the collagen extracts was observed. This study demonstrated that squid mantle has potential as an alternative source of collagen-derived materials.