Cultural heritage assets, including monuments, manuscripts, murals, and sculptures, are increasingly threatened by environmental pollutants, climate-induced degradation, and microbial colonization. Traditional conservation techniques, often reliant on chemical solvents and synthetic polymers, pose risks to both the integrity of heritage materials and the health of conservators. In response, biotechnology has emerged as a sustainable and targeted alternative for cultural heritage restoration. This chapter explores the principles and applications of biorestoration through microbial and enzymatic interventions. It highlights the mechanisms of material deterioration and the limitations of conventional methods, followed by an in-depth discussion on biocleaning, bio-consolidation, and bio-protection techniques. Case studies, including sulfate removal from the St. Augustine Tower in Goa using Pseudomonas and Arcobacter strains, and the enzymatic treatment of paper artifacts using crude chymopapain from papaya latex, illustrate the real-world efficacy of these methods.