Solids that possess acidic properties on their surfaces function as catalysts just like liquid acids, such as sulfuric acid and hydrochloric acid. By using solid acid catalysts, chemical processes become more productive and more environmentally friendly. In fact, solid acids are being used in many industrial chemical processes from the largest chemical process of catalytic cracking in petroleum refining to the synthesis of various fine chemicals. This book covers the fundamentals of solid acid catalysis, including its history and characterization, and discusses different types of catalysts and solid acid-catalyzed reactions as well as their industrial applications. It comprehensively covers from fundamentals to applications and will be useful for students, young researchers, and advanced researchers.