Her first volume of poetry, Side Effects, was published in 1978. She was "Writer-in-Residence" at St Martin's College, Lancaster (now University of Cumbria)(1983–85), as well as Northern Arts Fellow at Durham and Newcastle Universities.
In 1987 Fanthorpe went freelance, giving readings around the country and occasionally abroad. In 1994 she was nominated for the post of Professor of Poetry at Oxford. Her nine collections of poems were published by Peterloo Poets. Her Collected Poems came out in 2005. Many of her poems are for two voices. In her readings the other voice is that of Bristol academic and teacher R.V. "Rosie" Bailey, Fanthorpe's life partner of 44 years. The couple co-wrote a collection of poems, From Me To You: Love Poems, that was published in 2007 by Enitharmon.