The circular bioeconomy is an economic approach that merges the sustainable transformation of renewable biological materials into high-value products with circular economy principles. These principles strive to minimize waste, maximize resource efficiency, and establish self-sustaining production and consumption cycles. Circular bioeconomy is an emerging global research area and Chile as a country with both high biomass potentials and renewable energy capacities may become an important player for the production of green chemicals. This potential is showcased through four detailed case studies in the subsequent chapters. These studies span topics from the evaluation of lignocellulosic fuels using thermochemical methods to the innovative use of chemical synthesis in producing alternate fuels and eco-friendly base chemicals. The case studies also touch upon the complexities of gathering biomass and the logistics involved. Within this scope, there is an in-depth analysis of semi-mobile units designed for local biomass value addition, comparing different technologies and biomass types. As an illustration of introducing bio-derived products to commercial markets, one case study focuses on the launch of Nanofibrillated Cellulose (NFC) in the Chilean market. This present chapter provides some basic definitions regarding bioeconomy and circular bioeconomy and serves as an introduction to the following in-depth case studies.