She was born in Battersea, South London, England, to Namba Roy, a Jamaican writer and artist, and Yvonne Roy, an English actor and teacher. She grew up in England and received her B.A. in English from King's College London before moving to the U.S., where she currently resides. She completed her M.F.A. in creative writing at the University of Arkansas.
In 1988, she published her first collection of poetry, Wailing the Dead to Sleep. Celebrated American poet Nikki Giovanni wrote the introduction. In 1995, her second poetry collection, The Hummingbirds, was selected by poet Lucille Clifton as the winner of the Eighth Mountain Poetry Prize. In her first novel, Lady Moses, the protagonist is a woman whose father is a West African writer and whose mother is an English actress. HarperCollins published the book. Hotel Alleluia was her second novel, also published by HarperCollins.
Currently, she is the Director of Creative Writing at Virginia Tech in Blacksburg, Virginia, and was named Alumni Distinguished Professor of English. She is also the Vice President of the Association of Writers & Writing Programs.
Roy received some attention in April 2007 when, after the Virginia Tech massacre, it was revealed that she had in 2005 recognized spree shooter Seung-Hui Cho's behavior and writings. She warned campus authorities about him at that time, but as Cho had not made any specific threats, the authorities could take no action.