(David) Gwyther (Broome) Irwin (7 May 1931 – 18 October 2008) was a British abstract artist born in Basingstoke, Hampshire, who had lived much of his life in north Cornwall. He was educated in Dorset, at Goldsmiths College and at the Central School of Art in London 1951–1954. Irwin first came to prominence in 1957 with an exhibition at Gallery One, and another at Gimpel Fils in 1959. In 1964, he represented Britain at the Venice Biennale, along with Joe Tilson, Bernard Meadows and Roger Hilton. In 1960, he married Elizabeth Gowlett and they had two sons and one daughter.
His most famous artworks consisted of pictures assembled from newsprint and fragments of advertisements on paper, which he collected from the streets with his wife, and which were then worked up into collages often of fine delicacy and quite subtle shades. Some of his later works also used string, wood shavings, chalk and paint.
"Gwyther Irwin's latest collages...are evidently miracles of patient assembly...they set out to achieve the subtlest and slowest possible shifts in tonality from umber darkness to creamy light and back again. The patience, the subtlety, the muted gradations of every effect combine to produce an atmosphere of studied beauty." (The Times, 18 September 1959)
In the 1960s he taught at art schools in Hornsey, Corsham and Chelsea before becoming head of fine art at Brighton polytechnic between 1969 and 1984.