William Marshall Allen (born in 1957 in Philadelphia, Pennsylvania) is an American poet and visual artist.

His poetry is rooted in Imagism, history, politics, and art. His word art painting and prints are published by Clay Street Graphics Press. He is also represented by Cade Tompkins Fine Art. His poetry and art work is influenced by Concrete Poetry, Fluxus Art, and the ecphrastic tradition in literature and art.

William Allen grew up in Connecticut, receiving a bachelor's degree in Art from Wesleyan University and an M.A. in both American History and Creative Writing from New York University. He studied there with Philip Levine, Galway Kinnell, Sharon Olds, and Carolyn Forche.

He has worked as tugboat crew, U.A.W. training program instructor, and art trucker. He has taught poetry and writing at New York University, the Cooper Union for the Advancement of Science and Art, the School of Visual Arts, the Rhode Island School of Design and the University of Massachusetts Lowell. He went over to technical writing and then to the humanitarian assistance world in working as a communications specialist at the United Nations Development Programme (UNDP), then as Communications Officer at the United Nations Internatioal Computung Centre (UNICC) in New York. Currently he is a senior communications adviser with the UNICC.

He lives in Jackson Heights (Queens) and Rhinebeck, N.Y. with the artist Barbara Westermann, after living twenty years in the East Village of New York City, where they raised their daughter Lotte.