Breon O'Casey (30 April 1928 – 22 May 2011), the son of playwright Seán O'Casey, was a London-born and brought up artist, craftsman and jeweller closely associated with the St Ives School of painters and sculptors.
Breon was educated at Dartington Hall School in Devon and, following his national service duty, O'Casey attended the Anglo-French Art School, a small school in St John's Wood, London, based on the French model. He was an apprentice to Denis Mitchell and Dame Barbara Hepworth, which informed his own later career. In St Ives too, he began making jewelry as a side line, although his main occupation was always painting. He continued making jewellery until he was 70 years old.