The growing environmental concerns and increasing demand for eco-friendly materials have obliged researchers worldwide to explore naturally occurring biopolymers for potential applications in various fields. Cellulose is a renewable, biocompatible, non-toxic, and biodegradable biopolymer present in almost every plant cell wall. The hydrogels prepared from cellulose and its derivatives are appealing biomaterials for multidisciplinary fields due to their excellent properties. Hydrogels are crosslinked macromolecular networks capable of absorbing and releasing a substantial amount of water and other fluids. The high absorption efficiency and stimuli responsiveness of cellulose-based hydrogels have attracted significant attention in biomedical, agriculture, and flexible electronic fields. This is a comprehensive review of the synthesis and design of cellulose-based hydrogels and their structures, physicochemical properties, and applications in diverse areas. This review will be helpful for readers to understand cellulose and its functionalities to carry out further research and explore new applications as biomaterials.