She has taught in the Gaelscoil in Inchicore, in a school for adolescent travellers in Galway, and at the National University of Ireland in Galway. She served as editor of Poetry Ireland in 1995. Her work has appeared in a number of international anthologies and she has held writer-in-residence posts for Kerry County Council and Trent University Ontario (1994–95).
Cannon became a member of Aosdána, the affiliation of creative artists in Ireland, in 2004.
Her first book, Oar, (Salmon 1990, revised edition Gallery Press 2000) won the 1991 Brendan Behan Memorial Prize. It was followed by The Parchment Boat in 1997. Carrying the Songs: New and Selected Poems was published by Carcanet Press in 2007.