菌绿素，或者称细菌叶绿素（英文bacteriochlorophyll，简写BChl）是存在于多种细菌中的光合色素。它们和植物、真核藻类和蓝藻中的叶绿素结构上类似。含有菌绿素的细菌能进行光合作用，但不产生氧气。不同类群的细菌具有不同种类的菌绿素：

菌绿素c和d含有三个吡咯环和一个被还原的吡咯环，而其他菌绿素具有两个被还原的吡咯环。

Bacteriochlorophylls are photosynthetic pigments that occur in various phototrophic bacteria. They were discovered by C. B. van Niel in 1932. They are related to chlorophylls, which are the primary pigments in plants, algae, and cyanobacteria. Groups that contain bacteriochlorophyll conduct photosynthesis, but do not produce oxygen. They use wavelengths of light not absorbed by plants or Cyanobacteria. Different groups contain different types of bacteriochlorophyll: