Educated at Regent House School, Newtownards, Mark Shields was encouraged there by the art master William Bogle. He studied at the University of Ulster, graduating B.A. (Hons) in Fine Art in 1985. He was invited by the Lucy Simmonds Gallery in Hong Kong to take part in their 1995 Asian Art Fair and has had two shows at the Grosvenor Gallery, London.

In 1998 Shields was commissioned to paint the double portrait of Mary and Nicholas Robinson, which was unveiled at the National Gallery by the Taoiseach Bertie Ahern.