有机催化（Organocatalysis）是指只含碳、氢、硫和其他非金属元素的“有机催化剂”对化学反应的催化作用。这是目前有机合成中最热门的领域之一。它又可按照催化机理分为烯胺活化、亚胺离子活化、SOMO活化、氢键活化（硫脲催化、手性质子酸催化、寡肽催化、金鸡纳生物碱催化）、手性相转移催化剂活化和氮杂环卡宾活化等。

有机催化反应实际上很早就有报道。20世纪70年代发现的Hajos-Parrish-Eder-Sauer-Wiechert反应就是脯氨酸催化的分子内羟醛反应。2000年，List等将此反应用于不对称的分子间羟醛反应，在JACS上发表题为《脯氨酸催化的直接不对称羟醛反应》的通讯，标志着有机催化的复兴。同年MacMillan创制出“有机催化”一词，并提出一种全新的有机催化机理——亚胺活化。

In organic chemistry, the term organocatalysis (a portmanteau of the terms "organic" and "catalyst") refers to a form of catalysis, whereby the rate of a chemical reaction is increased by an organic catalyst referred to as an "organocatalyst" consisting of carbon, hydrogen, sulfur and other nonmetal elements found in organic compounds. Because of their similarity in composition and description, they are often mistaken as a misnomer for enzymes due to their comparable effects on reaction rates and forms of catalysis involved.