Natural polymers are readily available, nontoxic, biodegradable, biocompatible, highly reactive, and easily processable. To improve their physical-mechanical properties, biocomposites are formulated by incorporating nanometric fillers such as carbon-based nanomaterials and metal nanoparticles into polymeric matrices. Recently, biocomposites have received great research attention due to their improved mechanical properties and biocompatibility. Thanks to their advantages such as ultra-sensitivity and molecular specificity, the sensors have been utilized for various applications ranging from chemical and biological detection, environmental monitoring, and diagnostics. Polymeric membranes and their composite derivatives are the most preferred materials for sensor applications. Therefore, biocomposites are very promising materials for highly selective and sensitive sensors. This entry focuses on the various methods for preparing biopolymer composites and their recent advances in various sensor applications. In the main text, preparation methods of biocomposite-based electrodes are investigated and given a brief review about the analytical performance such as detection limit, reproducibility, stability, and response time. Finally, the advantages, current developments, and future scope of biopolymer composites in the biosensors applications are also discussed.