Polymers from natural resources established an important position owing to their easy availability, abundance, biocompatibility, and sustainability. Nowadays, human beings are aware about the environmental concerns and ecofriendly practices in every aspects of life, hence demand for such materials have increased more. Polymeric composites in macro, micro, and nano scale are popular for various applications such as energy production and storage, environmental cleaning, sensing, and packaging. This book chapter is all about to review the development of natural polymers-based composite materials for environmental applications and their mode of actions. What can be the further possibilities in this area are discussed by the end of chapter.