Biopolymer-based films have become leading alternatives to traditional fossil-based packaging plastics. Among the countless types of biopolymers with potential for such applications, films containing hydrolyzed collagen in their composition were scarcely explored. This study determined the effect of different loads of nano-SiO₂ (0, 2, 6, 8 and 10% w/w of sodium alginate) in the sodium alginate (SA) and hydrolyzed collagen (HC) blend films in terms of structure, thickness, mechanical properties, and thermal stability. The results indicated an improvement in the general mechanical and thermal behavior. Tensile strength increased from 18.2 MPa (control sample) to 25.4 MPa for the SA/HC film incorporated with 10% nano-SiO₂. In the same condition, the film's elongation at break improved impressively (from 19.5 to 35.8%). Thermal stability improved slightly for all proportions of nano-SiO₂. Therefore, the addition of nano-SiO₂ can be an easy and simple strategy to improve crucial properties of SA/HC blend films, increasing its performance for future application as sustainable packaging.