Phenol is one of a group of organic compounds identified by a group of hydroxyl (-OH) bound to a carbon atom that forms part of an aromatic ring. . The word phenol is also the specific name for its simplest member, mono hydroxybenzene (C6H5OH), as benzenol, or carbolic acid.

Alcohols are similar to phenols, but stronger bonds of hydrogen are formed. They are also more water-soluble than alcohols and have higher boiling points. At room temperature, phenols appear either as colourless liquids or white solids and can be extremely poisonous and caustic. Phenol was initially extracted from coal tar but is now produced from petroleum feedstocks on a wide scale.