AbstractBiomass is responsible for 25% of the primary energy supply in Brazil. However, future biomass demand will be influenced by many factors. This study evaluates potential pathways for the utilization of biomass in Brazil until 2050, while considering novel biobased sectors (renewable jet fuel and biochemicals), resource competition, and greenhouse gas (GHG) emissions. Whereas other least‐cost optimization models assess biobased options to meet energy and chemicals demand in Brazil to a limited extent, this study provides a detailed breakdown of biomass feedstock, including an extensive portfolio of biomass conversion technologies. A least‐cost optimization model is used to assess the demand for energy and chemicals, and the competition between biomass and other climate‐mitigation measures such as renewable power generation technologies, carbon capture and storage (CCS), and energy efficiency. Varied over the three scenarios, 86–96% of the sustainable biomass supply potential is used. Under more stringent mitigation targets, novel biomass conversion technologies start to play an important role: Biobased electricity production with CCS, jet fuel production from lignocellulosic biomass, and chemicals are partly produced from ethanol and bio‐naphtha. The modeling framework provides a transparent view of which type of biomass can be used for which specific purpose. It is therefore an interesting tool for future research, for example to examine the dynamic interaction with demand for land. © 2019 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.