Gillian Catherine Gill (born June 12, 1942) is a Welsh-American writer and academic who specializes in biography. She is the author of Agatha Christie (1990), Mary Baker Eddy (1998), Nightingales: The Extraordinary Upbringing and Curious Life of Miss Florence Nightingale (2004), and We Two: Victoria and Albert, Rulers, Partners, Rivals (2009).
Gill (née Scobie) was born in Cardiff, Wales. She attended Cardiff High School for Girls, and graduated from the University of Cambridge with a first-class honours degree in French, Italian, and Latin. She obtained her Ph.D. in March 1972, also from Cambridge, for a thesis entitled André Malraux: A Study of a Novelist. She emigrated to the United States after marrying, and taught at Northeastern University, Wellesley, Harvard, and Yale, where she was a fellow of Jonathan Edwards College and director of the Women's Studies Program.
- Agatha Christie: The Woman and Her Mysteries, Free Press, 1990.
- Mary Baker Eddy, Perseus Books, 1998.
- Nightingales: The Extraordinary Upbringing and Curious Life of Mods Florence Nightingale, Random House, 2004.
- We Two: Victoria and Albert, Rulers, Partners, Rivals, Ballantine Books, 2009.
- Luce Irigaray, Speculum of the Other Woman, Cornell University Press, 1985.
- Luce Irigaray, Marine Lover of Friedrich Nietzsche, Columbia University Press, 1991.
- Luce Irigaray, An Ethics of Sexual Difference, Cornell University Press, 1993.
- Luce Irigaray, Sexes and Genealogies, Columbia University Press, 1993.
- Lucienne Frappier-Mazur, Writing the Orgy: Power and Parody in Sade, University of Pennsylvania Press, 1996.
- Interview with Gillian Gill, Discussing Creativity, 2011 (video).
- Gardner, Martin. "Mind Over Matter", Los Angeles Times, August 22, 1999 (review of Gill's Mary Baker Eddy).
- Gill, Gillian. "Mrs. Eddy’s Voices", New York Review of Books, June 29, 2000.
- Gill, Gillian. "Excerpt from We Two", The New York Times, June 19, 2009.
- Leddy, Chuck. "The life, love of Britain’s Victorian power couple", Boston Globe, September 5, 2009 (review of Gill's We Two).
- Marshall, Megan. "Married With Children", The New York Times, June 19, 2009 (review of Gill's Nightingales).
- Moore, Charlotte. "It was a life of constant wrestling", The Daily Telegraph, September 14, 2004 (review of Gill's Nightingales).
- Mortimer, John. "Murder Most Tidy", The New York Times, October 14, 1990 (review of Gill's Agatha Christie).