Due to the boom in flexible and wearable electronics, eco-friendly and low-cost energy conversion devices are urgently needed. Triboelectric nanogenerators (TENGs) are widely used as power supplies due to their convenience and ability to convert low-frequency and low-intensity mechanical energy into electricity. Cellulose is widely used to construct TENGs due to its abundance, environmental friendliness, high mechanical strength, excellent triboelectric properties, and tunable surface chemistry. This review systematically summarizes recent research progress in cellulose-based green TENGs. First, the working principle, performance parameters, and influencing factors of TENGs are briefly introduced. Then, the classifications of cellulose are demonstrated. Subsequently, the application strategy and different forms of cellulose are comprehensively discussed. Furthermore, emerging applications of cellulose-based TENGs for environmentally-friendly energy harvesting, human-friendly wearable devices, medical and smart monitoring systems, and multi-functional applications are presented. Finally, the potential challenges and future development prospects of cellulose-based green TENGs are discussed.