'azophenol' originates from modern chemical English, specifically the combination of the prefix 'azo' (from French 'azo-' ultimately related to 'azote', originally referring to nitrogen) and 'phenol' (from German 'Phenol', from 'phenyl' + the '-ol' suffix), where 'azo-' referred to the azo group (−N=N−) and 'phenol' referred to an aromatic hydroxyl-containing ring.

'azophenol' was coined in the 19th century as chemists applied the 'azo-' prefix (derived via French from the term 'azote', used since the late 18th century) to aromatic compounds; combined with 'phenol' (a term established in chemical nomenclature by the mid-19th century), it became the standard name for azo-linked phenolic compounds.

Initially, 'azo' more generally denoted nitrogen-related chemical types and 'phenol' denoted benzene-derived alcohols; over time 'azophenol' came to mean specifically a compound with an −N=N− azo linkage attached to a phenolic ring.