Abstract: Foam-formed cellulose biocomposites are a promising technology for developing lightweight and sustainable packaging materials. In this work, we produce and characterize biocomposite foams based on methylcellulose (MC), cellulose fibers (CF), and lignin (LN). The results indicate that adding organosolv lignin to a foam prepared using MC and CF moderately increases Young’s modulus, protects the foam from the growth of Escherichia coli bacteria, and improves the hydrophobicity of the foam surface. This article concludes that organosolv lignin enhances many properties of cellulose biocomposite foams that are required in applications such as insulation, packaging, and cushioning. The optimization of the foam composition offers research directions toward the upscaling of the material solution to the industrial scale.