Born in Victoria, Katherine Gallagher has lived for many years in Europe and England. She graduated from the University of Melbourne in 1963 and taught in Melbourne high schools before moving first to London and then spending the years 1971-79 in Paris. She has lived in London since 1979. However, she maintains strong links with Australia and has contributed widely to poetry anthologies and journals both in Australia and overseas. Her published volumes of poetry include The Eye's Circle (1974), Fish-Rings on Water (1989) and Finding the Prince (1993).
Gallagher considers herself a 'late-starter' as she did not begin to write poetry until 1965 at the age of thirty. Her Australian experience features in her poetry, for example, 'Anzac Veteran' drawn from a Melbourne Anzac Day march in 1968. She has also written short stories, and in 1975 shared first prize with Finola Moorhead in the Sun Festival of Stories, Melbourne. A member of the British Haiku Society since its inception, Gallagher's book of Haiku verse Shifts was published in 1997.
From 2002-2008, Gallagher was Education Officer for Writers Inc and in 2008, she received a London Society of Authors' Foundation Award.