Gwendoline Nessie Foster was born in Brisbane and educated at Toowong State School and Brisbane Girls Grammar School. Until her marriage, she worked as a secretary and public servant. Her love of music was to be life-long and she studied piano and composition with musician and composer Robert Dalley-Scarlett and held the position of organist at All Saints Church, Brisbane. In 1945 she married linguist William Harwood and moved to Hobart, Tasmania where she taught music, worked as a medical secretary, raised a family and pursued her interest in modern philosophy, particularly the writings of Ludwig Wittgenstein.
Harwood's poetry and critical writing appeared regularly in Australian literary journals from the 1960s and her first volume, Poems, was published in 1963. A poet of wry wit, a natural parodist with a highly developed sense of fun and mischief, Harwood readily confessed to a fondness for 'wigs, jokes, puzzles, games' (Boundary Conditions, by Jennifer Strauss, p.25). Harwood published many of her poems under pseudonyms and during the early 1960s was associated, with Vincent Buckley, in several literary hoaxes especially that involving the Abelard and Eloisa acrostic sonnets with their uncomplimentary message to the editors of the Bulletin. The love of masquerade and the creation of personae such as Krote and Eisenbart is an important component of her poetic identity.
Gwen Harwood has also written libretti and choral works, some still unpublished, for composers Ian Cugley, Don Kay, James Penberthy and Larry Sitsky. A number of her poems have been set to music. Her letters to her close friend Thomas Riddell were published as Blessed City (1990) and a selection of her letters, A Steady Storm of Correspondence edited by Greg Kratzmann appeared in 2001.
Gwen Harwood was awarded honorary doctorates from the University of Tasmania, the University of Queensland and La Trobe University. She died in December 1995 in Hobart, aged 75 years. The Gwen Harwood Memorial Poetry Prize was established in 1996.