Computational approaches have provided new biological insights into the chemical mechanism of action of cellulases, which are used in the industrial production of bioethanol. Fine-grained methods, such as molecular dynamics and quantum mechanics, as well as coarse-grained methods, such as elastic network models, were used to investigate how the chemistry and structural dynamics of these enzymes contribute to their function. In this review, we highlight recent computational studies to understand this crucial biofuel enzyme class’s chemistry and structural dynamics, as well as their significance in revealing enzymatic mechanism of action. Computational methods can complement and amplify the findings of experimental methods, which can be used in tandem to create more efficient industrial enzymes.