Eugene O'Brien

• Eugene O'Brien (actor), American silent film and stage actor
• Eugene O'Brien (composer), American composer, and professor
• Eugene O'Brien Irish bridge engineer and academic
• Eugene O'Brien (playwright), Irish playwright, screenwriter and actor
• Eugene O'Brien (politician), Irish politician
• Eugene O'Brien (racing driver), British auto racing driver and coach
• Eugene W. O'Brien, American engineer, editor, and publisher