Armstrong, Arthur (1924–96), painter, was born 12 January 1924 at Carrickfergus, Co. Antrim, one of three sons among six children of Charlton Armstrong, house-painter and decorator. Soon after his birth the family moved to Belfast. His mother (née Howard) came from a wealthy Co. Down shipping family; however, by the mid 1920s the family was in straitened financial circumstances. He attended QUB in the early 1940s, where he initially studied political science and later architecture. Having an interest in art, which had been fostered by his father, he took classes for a short time in the early 1940s at Belfast School of Art. It was there he met Gerard Dillon (qv), who introduced him to George Campbell (qv) and Daniel O'Neill (qv). Armstrong was largely self-taught as an artist; it was his close association with Dillon and Campbell, both some years his senior, that proved to be the most important factor in his development. In Belfast in the early 1940s they associated with the Russian artist Daniel Nietzche, who emphasised to them the importance of personal expression.
After leaving university he worked at the Belfast Gas Office. At this point he was the main support for his widowed mother. Having saved some money, he left his job in 1946 to attempt to fulfil his ambition to paint full-time, producing a set of etchings with George Campbell, which were published by Walsh Studios. The following year he took work as a designer for Ulster Laces in Portadown. In 1957 he left for London in the hopes of finding greater opportunities as an artist. His friends Campbell and Dillon were already living there and Armstrong took lodgings with Dillon's sister at Abbey Road, north London. Though he continued to paint, he was unable to earn a living and so again had to take other work, this time in a Labour Exchange office. However, he was beginning to gain recognition. In 1957 he was awarded a travelling scholarship by the Council for the Encouragement of Music and the Arts (CEMA), which enabled him to travel to Spain. He continued to visit Spain throughout the 1960s, often to see Campbell, who spent much time there.
In 1961 he had his first solo exhibition at the CEMA gallery in Belfast. He came to live in Dublin in 1962; his work had already been exhibited there at the Irish Exhibition of Living Art in 1957 and 1958, and he continued to exhibit there annually from 1961 to 1965. During the 1960s and early 1970s his work was regularly included in the Oireachtas exhibition, at which he was awarded the Douglas Hyde (qv) gold medal in 1968. He also showed his work with the Hendriks and Tom Caldwell galleries in Dublin. Ultimately he was to have over seventy solo exhibitions throughout his career. By 1969, when he was elected an associate member of the RHA, he had established himself as one of the leading landscape painters in Ireland. In 1972 he became a full member of the RHA; he exhibited there regularly till 1977.
It was during this period that some of Armstrong's best work was produced. While landscape was his predominant theme, he never saw himself as a painter of particular views, rather he responded to the abstract qualities of a scene. He saw elements such as the sea, rocks or sky as a series of interlocking textures to be rendered expressively in oil paint. The western coastline of Ireland was a vital source of inspiration for him. Roundstone, Co. Galway, was a favoured base for painting trips in the company of Dillon and Campbell, who by this time were also living in Dublin.
In 1981 a retrospective exhibition of his work was organised by the Arts Council of Northern Ireland. Armstrong is represented in many major public and corporate collections in Ireland. From 1971 he lived at 28 Chelmsford Avenue, Ranelagh, Dublin, in a house he shared with Gerard Dillon. He died unmarried 13 January 1996 in Dublin. The contents of his studio were sold 3 February 1998.