The transition toward greener methodologies in analytical chemistry has intensified interest in biochar as a sustainable sorbent for food analysis. Derived from the pyrolysis of agro-industrial residues, biochar combines low-cost production with good properties such as high surface area, porosity, and surface tunability. This review provides a critical and feedstock-oriented overview of biochar applications in food sample preparation, categorizing sorbents based on their biomass origin (fruit waste, nut and seed residues, cereal by-products, lignocellulosic fibers, and wood waste). Each source is examined in terms of its physicochemical characteristics, extraction efficiency, and performance across different food matrices. Special emphasis is placed on sorbent modification strategies, the use of environmentally compatible desorption solvents, and the alignment of biochar use with green analytical chemistry (GAC) principles. Additionally, the review identifies key research gaps, limitations in analytical reproducibility, and challenges for regulatory acceptance. Overall, biochar emerges as a versatile and eco-efficient material with strong potential to enhance sustainability in food safety analysis.