Countries are duly focusing more on biomass resources because of the increasing oil crisis. Owing to their excellent properties, such as natural characteristics, good mechanical performance, and outstanding chemical properties, cellulose-based materials are highly valued as promising bio-derived nanomaterials, especially bacterial cellulose (BC). The main advantage lies in eliminating the problem of removing lignin and hemicellulose from woody cellulose. Moreover, the use of BC reduces the consumption of wood, the excessive use of which aggravates global warming. Herein, we summarize the applications of BC composites in filter, medical, and conductive materials, and other fields. This review contributes to further expand the applications of this renewable polymer.