As the principle structural polysaccharide in plants, cellulose has been extensively characterized over many decades. In recent years, however, exciting new cellulosic materials have been developed with nanoscale fibrillar structures that have particularly promising applications in the growing field of tissue engineering. The majority of recent studies on cellulose nanomaterials for tissue engineering have employed bacterial cellulose, a material with a profile of properties unique among biomaterials commonly used in tissue engineering scaffolds. In addition, a number of recent studies have explored the biomedical applications of discrete colloidal nanocellulose fibrils known as cellulose nanowhiskers or cellulose nanocrystals. The literature on bacterial cellulose scaffolds for tissue engineering is reviewed, and studies on the biocompatibility of cellulose nanowhiskers and their potential for tissue engineering are discussed. Challenges for future development of these materials and potential future advances are also considered.