Publisher Summary This chapter discusses design of industrial catalysts. Catalysts play important roles in the production of bulk chemicals such as sulphuric acid, ammonia, nitric acid and methanol, and catalysis is essential in hydrocarbon processing such as hydrocracking, hydrodesulphurization, and catalytic reforming. The desire to reduce production cost and energy consumption in industry has been a major driving force for the development of new catalysts and catalytic processes, and in the past decades an increased focus on environmental protection has called for new catalysts for removal of SO2, NOx and organic compounds from off-gases in the chemical industry, from power plants, refineries and from autoexhaust. This chapter discusses the steps involved in the development and design of a new SO2 oxidation catalyst VK69 that was introduced to the market in 1996 by Haldor Topsøe. The strategy and many of the methods are generally applicable to heterogeneous fixed bed catalysts, partly to fluid and slurry bed catalysts, and less relevant for homogeneous catalysts as found in organic synthesis and enzymatic reactions.