Seán O'Sullivan (20 June 1906 – 4 April 1964) was an Irish painter. He began exhibiting at the Royal Hibernian Academy (RHA) in 1926, at the age of 20, contributing an average of six paintings a year until his death.
Primarily a portrait painter, O'Sullivan composed works featuring many of the leading political and cultural figures in Ireland, including Éamon de Valera, Douglas Hyde, W B Yeats, and James Joyce.
He designed the cover for the Capuchin Annual in 1930.