希尔反应（Hill reaction）是指在光照条件下，绿色植物的叶绿体裂解水，释放氧气并还原电子受体的反应。该反应由英国科学家罗伯特·希尔发现，故称“希尔反应”。 原始文献发表于英国《自然》（Nature）杂志：Hill R. (1937) Oxygen evolved by isolated chloroplasts. Nature 133, 881.

参见光合作用。

Discovered in 1937 by Robin Hill, Hill reagents allowed the discovery of electron transport chains during photosynthesis. These are dyes that act as artificial electron acceptors, changing color when they are reduced. An example of a Hill reagent is 2,6-dichlorophelindophenol (DCPIP).