L. Timmel Duchamp is best known as the author of the five-volume Marq'ssan Cycle and the founder and publisher of Aqueduct Press. She is the author of two collections of short fiction: Love's Body, Dancing in Time (Aqueduct, 2004), which was shortlisted for the Tiptree and includes the Sturgeon-finalist story, "Dance at the Edge," the Sidewise Award-nominated, "The Heloise Archive," and the Tiptree-shortlisted "The Apprenticeship of Isabetta di Pietro Cavazzi"; and Never at Home (Aqueduct, 2011), which includes a 2011Tiptree-Honor List story, and co-author, with Maureen McHugh, of a mini-collection, Plugged In (Aqueduct, 2008, published in conjunction with the authors' being GoHs at WisCon). Her Marq'ssan Cycle (which won special recognition from the James Tiptree Award jury), consists of Alanya to Alanya (Aqueduct, 2005), Renegade (Aqueduct, 2006), and Tsunami (Aqueduct, 2007), Blood in the Fruit (Aqueduct, 2007), and Stretto (Aqueduct, 2008). She has also published the short novel, The Red Rose Rages (Bleeding) (Aqueduct, 2005), the novella De Secretis Mulierum (Aqueduct, 2008); dozens more short stories, including "Motherhood, Etc." (short-listed for the Tiptree) and "LivingTrust" (Nebula and Homer Award finalist).

She has published a good deal of nonfiction, from reviews for Strange Horizons and The American Book Review to essays for NYRSF and Extrapolation; an essay collection, The Grand Conversation (Aqueduct, 2004); and most recently, "Mad Scientists, Chimps, and Mice with Human Brains: Collapsing Boundaries in Science Fiction" in Parabolas (Wesleyan University Press, 2013, ed. Brian Attebery and Veronica Hollinger), and "Real Mothers, a Faggot Uncle, and the Name of the Father: Samuel R. Delany's Feminist Revisions of the Story of SF" in a special Samuel R. Delany issue of Annals of Scholarship, ed. by Kenneth James (2013).

Since 2011, she has been the Features Editor of The Cascadia Subduction Zone. She is also the editor of Talking Back: Epistolary Fantasies (Aqueduct, 2006), The WisCon Chronicles, Vol. 1 (Aqueduct, 2007), Narrative Power: Encounters, Celebrations, Struggles (Aqueduct Press, 2010), Missing Links and Secret Histories: A Selection of Wikipedia Entries from across the Known Multiverse (Aqueduct Press, 2013), and co-editor, with Eileen Gunn, of The WisCon Chronicles, Vol. 2: Provocative essays on feminism, race, revolution, and the future (Aqueduct, 2008).

Duchamp is the founder and publisher of Aqueduct Press, which has released numerous award-winning books, including Gwyneth Jones's Life (the Philip K. Dick Award), Ursula K. Le Guin's Cheek by Jowl (the Locus Award), Nisi Shawl's Filterhouse (the James Tiptree Jr. Award), Vandana Singh's Distances (the Carl Brandon Society's Parallax Award), and Andrea Hairston's Mindscape (the Carl Brandon Society's Parallax Award) and Redwood and Wildfire (the James Tiptree Jr. Award and the Carl Brandon Society's Kindred Award). In 2008 she appeared as a Guest of Honor at WisCon. In 2009-2010 she was awarded the Neil Clark Special Achievement Award ("recognizing individuals who are proactive behind the scenes but whose efforts often don't receive the measure of public recognition they deserve").