Sean O'Sullivan

• Seán Ó Súilleabháin, folklorist involved in the Irish Folklore Commission
• Sean O'Sullivan (baseball), Major League Baseball pitcher
• Sean O'Sullivan (engineer), entrepreneur and engineer
• Seán O'Sullivan (footballer), Irish Gaelic footballer who plays for Kerry and Cromane
• Seán O'Sullivan (painter), Irish painter
• Sean O'Sullivan (priest), Canadian politician and priest
• Sean O'Sullivan (rugby league), Australian rugby league player
• Sean O'Sullivan (snooker player), English snooker player
• Shawn O'Sullivan, retired Canadian boxer