Born in Ilkley, Yorkshire, Hyatt went to study at Leeds College of Art, 1948-1952 and then the Royal College of Art from 1954 to 1958 where he edited Ark magazine. The artist was awarded the Royal Scholar prize in 1955 and the J. Andrew Lloyd Scholarship for landscape painting in 1958. Between 1959-1964 Hyatt was a visiting lecturer at Kingston School of Art before returning to Yorkshire to teach at Leeds College of Art, later becoming senior lecturer at Leeds Polytechnic.
He has held many solo exhibitions beginning in 1960 with a series of shows at the New Art Centre in 1960 to 1966; exhibited at the University of York, Waddingtons in 1975, Waddingtons & Tooth in 1977, Austin Desmond Fine Art in 1989 and the Dean Clough Contemporary Art Gallery, Halifax in 1991 and 1992. Group shows included the Jon Moore, the Cincinnati Biennial and the Arts Council travelling exhibitions.
Hyatt's work is held in the Museum of Modern Art in New York; the Contemporary Art Society and the Nutfield Foundation. His paintings and drawings feature in the public collections of major institutions such as the Universities of Leeds, Oxford, Harvard and Yale as well as the De Beers collection. He is also a published poet and writer.