Sean O’Sullivan was one of the most distinguished portrait painters and printmakers in twentieth-century Ireland, whose subjects included many of the leading political and cultural figures of his era.

He competed in the painting section of the arts competition at the 1932 Los Angeles Olympic Games, submitting a portrait entitled Cyclone Warren, Negro Boxer – a depiction of Joseph “Billy” Warren, an American boxer known as “Cyclone” who settled in Dublin towards the end of his career and became a well-known figure in the city.

O’Sullivan studied at the Dublin Metropolitan School of Art, where he won a scholarship, before studying lithography at the Central School of Arts and Crafts in London and then fine art painting and figure painting in Paris at the Academie Colarossi and La Grande Chaumiere.

In Paris, he was a neighbour of the sculptor Antoine Bourdelle. Returning to London in the mid-1920s, he worked in book design and printmaking before moving back to Dublin, where he focused on portraiture in oils, crayon and pencil, as well as painting murals, designing postage stamps and teaching at the Dublin Metropolitan School of Art. Fluent in Irish and French, he also painted landscapes of the west of Ireland.