Joan Daugherty Chittister, O.S.B. (born April 26, 1936), is an American Benedictine nun, theologian, author, and speaker. She has served as Benedictine prioress and Benedictine federation president, president of the Leadership Conference of Women Religious, and co-chair of the Global Peace Initiative of Women.
 Chittister was born on April 26, 1936, to Daniel and Loretta Daugherty. Her father died when she was very young and her mother married Harold Chittister. Joan Chittister described her step-father as a violently abusive alcoholic.
 She was educated  by Sisters of St. Joseph, and later attended St. Benedict Academy in Erie, Pennsylvania. Chittister holds a master's degree from the University of Notre Dame and a Ph.D. in speech communication theory from Penn State University. She is also an elected fellow of St. Edmunds College at the University of Cambridge.
 In 1971, Chittister was elected president of the Federation of St. Scholastica, a federation of twenty monasteries of Benedictine women in the United States and Mexico, established in 1922. She was a prioress of the Benedictine Sisters of Erie, Pennsylvania, for 12 years and is a past president of the Leadership Conference of Women Religious. She serves as co-chair of the Global Peace Initiative of Women (2016-2019), an inclusive international network of spiritual and community leaders. With this organization, she works to bring a spiritual perspective to conflict resolution fueled by pressing economic and ecological crises across the globe.
 Chittister says that women's ordination has never been her primary focus. Her books deal with monasticism, justice and equality especially for women in church and society, interfaith topics, peace and others. She has won 16 Catholic Press Association awards for her books and numerous other awards for her work, including 12 honorary degrees from US universities.
 She writes a column for the National Catholic Reporter, "From Where I Stand".
 Penn State University holds the Joan D. Chittister Literary Archives.
 A biography of Chittister was released by Orbis Books in October 2015, Joan Chittister: Her Journey from Certainty to Faith by Tom Roberts.
 Chittister's stances on contraception and women's ordination are known to contradict the official teachings of the Catholic Church. She was one of two nuns prohibited by Church authorities from attending the first Women's Ordination Worldwide conference on June 30, 2001. However, she not only attended, but gave the opening address. In another instance, Chittister rejected the Church's strictures against the 23 nuns who ran an advertisement in the New York Times attacking the Church's teaching on abortion.
 Chittister has authored over 50 books and over 700 articles in numerous journals and magazines including: America, US Catholic, Sojourners, Spirituality (Dublin), and The Tablet (London). She is a regular contributor to NCRonline.org and HuffingtonPost.com, appeared on Oprah Winfrey's Super Soul Sunday in March 2015 and in May 2019, on Meet the Press with Tim Russert and Now with Bill Moyers.
 She is the executive director of "Benetvision", a publications ministry of the Benedictine Sisters of Erie.
 Joan Chittister: Essential Writings, a compilation from her best writing from books, articles and speeches, was published by Orbis Books in August 2014 (ed. Mary Lou Kownacki, OSB, Mary Hembrow Snyder, PhD). In 2019, Dear Joan: conversations with women in the church, editor Jessie Bazan was published by Twenty-third Publ.