Daniel O’Neill was born in Belfast in 1920. Educated at At John’s Public Elementary School, he was passionately interested in art. He attended a few life classes at the the Belfast College of Art, and worked for a short spell in the Belfast studio of Sidney Smith. At this time he met Gerard Dillon. O’Neill was particularly interested in the Italian primitives.

An electrician in the Belfast Corporation Transport Department, he worked on the night shift and painted at home during the day. Changing his job to the shipyards, the same lifestyle continued. In 1945 he received encouragement – and financial help – from the Dublin dealer, Victor Waddington, hence his decision to end the ‘double life’. In 1946 he held a one-person show at the Victor Waddington Galleries, selling nearly all the canvases. The Irish Times thought he was romantic ‘in a theatrical and mannered way’.

O’Neill was mostly a landscape and figure painter. His world is dreamy, rather withdrawn, full of brooding beauties, erotic reveries, figures in half-light, flowers, moody interiors.

O’Neill’s work began to appear in London abroad, in New York in 1947 and Beverly Hills, California, in 1948. He first exhibited at the Royal Hibernian Academy in 1947, and between then and 1963 contributed twenty-three works, but he showed regularly in Dublin with the Irish Exhibition of Living Art, and also exhibited at the Oireachtas.