Lignocellulosic biomass is a widely available, renewable resource with significant potential for sustainable bioconversion. However, its effective utilization requires a sequence of processing steps, primarily pretreatment followed by enzymatic hydrolysis, to release fermentable sugars from structural carbohydrates. These processes are commonly implemented in various reactor configurations, including counter-current, percolation, plug-flow, and shrinking-bed reactors operating under batch, semicontinuous, or continuous modes. Such systems offer distinct advantages, including the capacity to handle high solid loadings, generate sugar-rich hydrolysates, and minimize water usage and wastewater production. This chapter presents a concise review of current literature on the application of these reactor technologies in the pretreatment and hydrolysis of lignocellulosic biomass. The insights provided aim to inform the development of more efficient and environmentally sustainable bioconversion strategies for the advancement of bio-based industries.