Norah McGuinness trained at the Dublin Metropolitan School of Art and at Chelsea Polytechnic in London before spending the 1920s working in Dublin as a book illustrator and stage designer. She married the editor Geoffrey Phibbs, but they divorced in 1929. The same year she followed the advice of Mainie Jellett and travelled to Paris to work at the studio of André Lhote. From there she moved to London where she was a member of the avant-garde London Group, from 1937-39 she lived in New York. After New York, she returned to Ireland, settled in Dublin and concentrated on painting.
Although her work remained figurative, she painted vivid, highly coloured landscapes, her work shows the cubist influence of Lhote and she was associated with the modern movement in Ireland. She helped found the Irish Exhibition of Living Art in 1943 and became its president in 1944 after the death of Mainie Jellett.