Cellulose, the most abundant polymer on this planet, is widely produced by plants and many bacterial species. Certain cyanobacterial species also synthetize cellulose, though typically at much lower yields compared to other bacteria. Cyanobacteria are particularly intriguing in this context, as they uniquely combine the features of Gram-negative bacteria with plant-like features, such as oxygenic photosynthesis and CO₂ fixation. This review highlights the structure and biosynthesis of cellulose in cyanobacteria, and explores the distinctive features compared with those of bacterial and vascular plants. We also discuss current strategies to enhance cellulose production in cyanobacteria through genetic engineering, synthetic redesign and environmental modulation, and propose key knowledge gaps. This review thus provides a foundation for advancing both fundamental understanding and the development of sustainable cellulose-based biotechnologies.