'festivalgoer' originates from Modern English, formed by compounding the noun 'festival' and the agentive 'goer' (from the verb 'go').

'festival' comes from Latin 'festivus' via Old French 'festival' into Middle English 'festival'; the agent noun 'goer' derives from Middle English 'goer', ultimately from Old English 'gān' (to go). These elements were joined in Modern English to form the compound 'festivalgoer'.

Initially it meant literally 'a person who goes to a festival'; over time the sense has remained essentially the same, now specifically referring to someone who attends festivals as an audience member or participant rather than as a performer or organizer.