AbstractNovolac resins are produced by reacting phenol and formaldehyde, which are both conventionally obtained from petroleum refining. However, phenolic compounds present in bio‐oil obtained via fast pyrolysis of lignocellulosic biomass can be used to partially substitute petroleum‐derived phenol. Thus, the objective of this study was to analyze the techno‐economic feasibility of producing novolac resin by partially substituting petroleum‐derived phenol with biomass‐based phenol in the U.S. The analysis was done at two different annual novolac resin production capacities of 25, 000 and 100, 000 t, respectively, representing the existing small‐ and large‐scale resin production facilities in the U.S. Mass balance and energy analyses of the system were performed to estimate resources (equipment, raw materials, consumables, utilities, and labor) requirements, capital and operating costs, and the financial parameters, including the minimum selling price (MSP). The MSPs for biomass‐based novolac resin for 25, 000 and 100, 000 t capacities were estimated to be $1,585 t–1 and $1,250/t–1, respectively, which falls below its current market price range ($1,700‐3,200 t–1). The bio‐oil to phenol substitution ratio, phenol content in bio‐oil, phenol cost, plant size, biomass feedstock cost, and resin synthesis residence time were the most sensitive parameters affecting the production cost and MSP of novolac resin. The production of biobased novolac resin has the potential to be economically feasible at the current state of technology, and could be an important outlet for diversifying the use of bio‐oil. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd