The study offers a comprehensive overview of biosorption technology’s application in oil spill recovery and oil–water separation, drawing attention from academia, research, and industry for its versatile potential. In this context, the focus is directed towards non-conventional, cost-effective adsorbents, primarily cellulose and keratin-based materials, which exhibit promising attributes for effective oil spill cleanup. The study arrives at several key insights: Firstly, unconventional adsorbents, owing to their natural abundance, biodegradability, and economic viability, outperform traditional counterparts in oil spill recovery efforts. Secondly, the optimal oil spill sorbent necessitates tailored qualities such as lipophilicity, hydrophobicity, biodegradability, and exceptional absorption and retention capabilities. To address the limitations of poor oleophilic and hydrophobic traits of sorbents, various mechanical, thermal, and chemical modification techniques are explored and found to be effective. The sorption capacity is revealed to be a multifaceted interplay between the sorbent’s attributes, spilled oil characteristics, and the surrounding marine environment. Notably, economic analyses emerge as a critical factor in evaluating the practicality of biosorption technology for large-scale industrial applications. Looking ahead, the study underscores the importance of future research in refining chemical modifications to optimize biosorbents’ oil absorption capabilities while mitigating ecological impacts. In essence, this study underscores biosorption technology’s considerable promise and the persistent need for innovative research to harness its full potential in addressing real-world oil spill challenges within a framework of environmental sustainability.