费托合成（Fischer–Tropsch process），又称F-T合成，是以合成气（一氧化碳和氢气的混合气体）为原料在催化剂和适当条件下合成以液态的烃或碳氢化合物（hydrocarbon）的工艺过程。在1925年，由就职于位于鲁尔河畔米尔海姆市马克斯·普朗克煤炭研究所的德国化学家弗朗兹·费歇尔和汉斯·托罗普施所开发的。这个过程是气体液化技术的一个关键组成部分，它通常是从煤，天然气或生物质产生合成润滑油与合成燃料。费托合成作为低硫柴油燃料的来源而得到间歇性的关注，用以解决基于石油的烃类的供应或成本问题。

The Fischer–Tropsch process is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. It was first developed by Franz Fischer and Hans Tropsch at the Kaiser-Wilhelm-Institut für Kohlenforschung in Mülheim an der Ruhr, Germany, in 1925. The process, a key component of gas to liquids technology, produces a synthetic lubrication oil and synthetic fuel, typically from coal, natural gas, or biomass. The Fischer–Tropsch process has received intermittent attention as a source of low-sulfur diesel fuel and to address the supply or cost of petroleum-derived hydrocarbons. A Fischer–Tropsch-type process has also been suggested to have produced a few of the building blocks of DNA and RNA within asteroids.