John Harold Hewitt was born in Belfast, Ireland, was the most significant Irish poet to emerge before the 1960s generation of poets that included Seamus Heaney, Derek Mahon and Michael Longley. He was appointed the first writer-in-residence at Queen's University Belfast in 1976. His collections include The Day of the Corncrake (1969) and Out of My Time: Poems 1969 to 1974 (1974). He was also made a Freeman of the City of Belfast in 1983, and was awarded honorary doctorates from the University of Ulster and Queen's University Belfast.
From November 1930 to 1957, Hewitt held positions in the Belfast Museum Art Gallery.
Hewitt was appointed Director of the Herbert Art Gallery & Museum where he worked until retirement in 1972.