Computational fluid dynamics (CFD) is considered as a powerful modeling tool in the chemical technology. It can be used to gain fundamental understanding and therefore complement experiments, carry out sensitivity studies, or design highly customized reactor equipment if coupled with Computer‐Aided Design (CAD) and additive manufacturing (3D printing). CFD models in chemical engineering are challenging, since most of the problems are multiscale, multiphase, and multiphysics in nature. This article presents the fundamentals of governing equations, mesh generation, and solving with the finite volume method as well as modeling approaches for special phenomena being relevant for chemical engineering, such as heat transfer, turbulence, chemically reacting flow, and multiphase flow. Finally, the recent progress of CFD models for stirred‐tank reactors, packed‐bed reactors, and fluidized‐bed reactors is discussed.