Educated at Fort Street Boys High School, Sydney, Raymond McGrath graduated in 1926 from the University of Sydney with a Bachelor of Architecture with First Class Honours, the University Medal and the Wentworth Travelling Scholarship. As an undergraduate student he wrote poems and short stories, many of which were published in Hermes. While at university he also studied painting at the Julian Ashton School, bookbinding with Arthur Taylor and modelling with Rayner Hoff. In late 1926, McGrath moved to London and studied at the Westminster School of Art, becoming the first research student of Architecture at Clare College, Cambridge. While travelling in Europe he wrote and contributed articles, poems and short stories to Architectural Review and Lady Clare Magazine.
McGrath established a private practice, winning architectural and design awards, consulting to the British Broadcasting Commission and designing for Poole pottery. In 1940 he became an official war artist, mainly drawing sketches of aircraft production. For twenty years from 1948, he was principal architect for the Office of Public Works, Dublin, and in 1970 he was appointed Professor of Architecture at the Royal Hibernian Academy, a position he held until his death. Some of his other published works include Twentieth Century Houses (1934), Glass in Architecture and Decoration, with A. C. Frost (1937). An exhibition of his prints was held at Deutsher Galleries, Melbourne in May 1979.