Henderson, born in Kitchener, Ontario, has a PhD in Canadian Literature from York University. He has published many articles and reviews, and is also the Director of Wilfrid Laurier University Press and a photographer. Henderson has worked as a university instructor, a phone jack installer, a traffic counter, a shipper/receiver, and a rock drummer.
He is the author of eight collections of poetry and a deck of visual poem-cards. His work has been published in many small magazines. In the 1970s Henderson was a founding editor of RUNE.
He lives with his wife, Charlene, son, Adrian and step son, Sean.
His poetry and literary criticism has appeared in Arc, Antigonish Review, Canadian Forum, Canadian Literature, CVII, Descant, ECW, The fiddlehead, Prism, Quarry, Rampike, Rune (of which he was a founding editor for its decade of existence), Scrivener and Writ since 1974.