Simpson received her B.A. and M.A. degrees from Queen’s University, and a diploma in Fine Arts from the Ontario College of Art and Design. Subsequently, she worked as a CUSO volunteer English teacher for two years in Nigeria. She was the co-winner of the 1997 Journey Prize, awarded for her short story Dreaming Snow. Her second collection of poetry, Loop (2003), was the winner of the 2004 Canadian Griffin Poetry Prize. Her second novel, Falling (2008),a Canadian bestseller, was the winner of the Dartmouth Fiction Award. It was long-listed for the IMPAC Dublin Literary Award. She has also written a book of essays on poetics, The Marram Grass: Poetry and Otherness (2009).
During 2009-2010, Simpson was Writer-In-Residence at the Saskatoon Public Library. She has been Writer-in-Residence at the University of New Brunswick and Artist-in-Residence at the Medical Humanities Program at Dalhousie University. She has also been a faculty member at the Banff Centre. She lives in Antigonish, Nova Scotia, where she teaches part-time at St. Francis Xavier University.