Ryanair has been ordered to pay £8,000 compensation for breaching equality legislation by advertising a job vacancy for a "young and dynamic professional".
The case was taken by the Equality Authority because the job advertisement contravened regulations prohibiting discrimination on the grounds of age.
When confronted, the airline claimed that young was "a state of mind" and not an actual age.
Along with the fine, Ryanair has been told to take a comprehensive review of its equal opportunity policies.
The Equality Authority said it hopes the case will focus attention on what it describes as "the casual and accepted discrimination" experienced by older people in the workplace.
It said such discrimination is based on widely-held stereotypes that your age determines your capacity.