'azobenzene' originates from the combining form 'azo-' (from French 'azote', ultimately from Greek elements 'a-' meaning 'not' and 'zóē' meaning 'life', used historically for nitrogen-related terms) combined with 'benzene' (from 'benzoin' via New Latin/German 'Benzol'), where 'azo-' meant 'nitrogen-containing (specifically relating to -N=N- linkage)' and 'benzene' referred to the aromatic hydrocarbon framework.

'azobenzene' was formed in 19th-century chemical nomenclature by joining the prefix 'azo-' (used to name compounds containing nitrogen–nitrogen double bonds) with 'benzene' (a name that evolved from 'benzoin' and 'benzol' into the modern 'benzene'), producing the modern compound name 'azobenzene'.

Initially, components of the name referred separately to 'azo' (nitrogen-related) and 'benzene' (the aromatic ring). Over time the term 'azobenzene' came to denote the specific diphenyldiazene molecule (C12H10N2) known for its dye chemistry and photoisomerization behavior.