In pursuit of a more green and sustainable society, the preparation of versatile chemicals from renewable biomass is essential. Nitrogen-containing chemicals, as compared with hydrocarbon fuels or oxygen-containing compounds, usually have higher values and play key roles in modern industry. The industrial synthesis of nitrogen-containing chemicals relies heavily on the Haber–Bosch process, a high-energy-consumption and environment-polluting process. Therefore, the production of these organonitrogen chemicals from biomass has attracted increasing interest in recent years. Chitin is the most abundant nitrogen-containing biopolymer on earth, and its monomer N-acetylglucosamine (GlcNAc) not only has great application values in multiple areas, but also is a key intermediate for the conversion of chitin to other organonitrogen compounds. This review provides a comprehensive summary and perspective of the latest cutting-edge innovations on biomass conversion to GlcNAc. Biological methods, chemical methods as well as combined methods for GlcNAc preparation are systematically elaborated, and their respective advantages and disadvantages in terms of product yield, process safety, economy, efficiency, and environmental friendliness are discussed. To achieve an economic, environmentally friendly, and efficient production of GlcNAc from renewable biomass, the development of combined methods that involve multiple actions in a synergistic way under mild and green conditions should be the focus of future research.