Castillo was born and raised in an inner city barrio of Chicago, Illinois. After completing undergraduate studies, she immediately began teaching college courses. She earned her Master's degree in Latin American and Caribbean studies from the University of Chicago with a thesis entitled "The Idealization and Reality of the Mexican Indian Woman". She received her doctorate from the University of Bremen, Germany, in American studies in 1991. In lieu of a traditional dissertation, she submitted the essays later collected in her highly acclaimed work Massacre of the Dreamers.

Castillo writes about Chicana feminism, which she dubs "Xicanisma", and her work centers on issues of identity, racism, and classism. Many of her protagonists are fiercely independent, sometimes lesbian, women. Her "imaginative fiction" shows the influence of magical realism. For example, the novel Sapogonia is about a fictional country that is the home to all mestizos. Much of her work has been translated into Spanish. She has also contributed articles and essays to such publications as the Los Angeles Times and Salon.

Her papers are housed at the California Ethnic and Multicultural Archives at the University of California, Santa Barbara.

So Far from God, Castillo's third novel (1993), might best be described as a telenovela, in which intimate details of people’s loves and losses are told, and what will happen in the next day’s broadcast is hinted at. The novel, set in the tiny village of Tome, New Mexico, employs magic realism to examine the lives of Mexican-American women on the borders. The character Sofi, a middle-aged single mother, and her four daughters live at a crossroads between Chicano, Mexican, Spanish, and First Nations cultures. While juggling her small business duties and childcare, Sofi confronts both the modern technological moment and ageless traditions of birth, growth, and loss; for comfort, she and her neighbors are immersed in competing religious traditions of Catholicism, curanderismo, and folk-traditions concerning the nature of the spirit.

As the novel opens, La Loca, Sofi’s youngest daughter, dies, examines the details of hell, and then comes back to Tome to live. Since she has experienced much of the spirit world, it is no wonder that she has epileptic fits, cannot stand the smell of people (preferring the company of horses), frequently talks with the Mexican-American folk character La Llorona, and despite her lack of body, dies once more of AIDS. Sofi’s next youngest daughter’s, barhopping lifestyle leads to her rape, but not by a man, by la Malogra, a New Mexican folkloric monster said to haunt empty highways. Miraculously healed, this daughter, whose name is Caridad, trains to become a curandera (traditional healer), and joins the annual pilgrimage to Chimayo, where she meets her beloved, a woman. Francisco, the village santero (saint-carver), stalks Caridad, only to see her leap, with her beloved, from the great heights of Acoma, the pueblo built atop a mountain which was difficult for Spanish conquerors to take by surprise; and thus her exit enacts freedom from her male pursuer, freedom from “conquest,” and untouchable and undying faith in her love. Fe, the next daughter in line, immerses herself in a relentless pursuit of the American Dream, which for her include a husband and a house of her own. Led by her employer’s promises of more money, she undertakes jobs that place her in contact with dangerous chemicals, until she sickens and dies of cancer. Sofi’s eldest daughter, Esperanza, gains an education and moves away to have a life independent of that of the village. However, her job as news anchorwoman takes her to Saudi Arabia, where she is killed in the war. Her spirit walks with that of La Llorona in Tome’s acequia (irrigation channel) and frequently converses with La Loca.

At the novel’s conclusion, Sofi is strengthened, not destroyed, by the loss of her daughters and turns away from the traditional life of the home-maker to the life of a politician and reformer, seeking to create a weaving cooperative. Interestingly, names in this novel form a kind of allegory. Sofi, whose name means “wisdom,” having lost, in her daughters, the Christian tenets of faith (Fe), hope (Esperanza) and charity (Caridad), places her wisdom and strength at the service of her neighbors so that they may continue to survive.

So Far from God is set within the United States, but as a border novel, it is neither Mexican nor American, but a hybrid form which records history and traditions in both cultures. Its title is from a quotation by Mexican president Porfirio Diaz ["Pobre Mexico tan lejos de Dios y tan cerca de los Estados Unidos." ("Poor Mexico so far from God and so close to the United States.")], a man who carried both Spanish and Indian genes, and who was popular for a time for refusing to join with the last foreign emperor of Mexico, Maximilian I of Mexico.

Novels

• The Mixquiahuala Letters. Binghamton, N.Y. : Bilingual Press/Editorial Bilingue, 1986. ISBN 0-916950-67-0
• An anti-romance in 3/8 meter. Tempe, Arizona: Bilingual Press/Editorial Bilingüe, 1990. ISBN 0-916950-95-6
• So Far From God. New York: W.W. Norton, 1993. ISBN 0-393-03490-9
• Peel My Love Like an Onion. New York : Doubleday, 1999. ISBN 0-385-49676-1
• An Aztec Chant. New York: Dutton Books, 2000. ISBN 0-525-45856-5
• A Novel in Verse. Willimantic, Connecticut: Curbstone Press, 2005. ISBN 978-1-931896-20-7
• The Guardians. New York: Random House, 2007. ISBN 978-1-4000-6500-4

Story collections

• Loverboys. New York: W.W. Norton, 1996. ISBN 0-393-03959-5

Poetry

• Otro Canto. Chicago: Alternativa Publications, 1977.
• The Invitation. 1979
• Women Are Not Roses. Houston: Arte Público Press, 1984. ISBN 0-934770-28-X
• My Father Was a Toltec and selected poems, 1973-1988. New York: Norton, 1995. ISBN 0-393-03718-5
• I Ask the Impossible. New York: Anchor Books, 2000. ISBN 0-385-72073-4
• "Women Don't Riot"

Non-fiction

• Massacre of the Dreamers: Essays on Xicanisma. Albuquerque: University of New Mexico Press, 1994. ISBN 0-8263-1554-2

Translations

• Este Puente, Mi Espalda: Voces de Mujeres Tercermundistas en los Estados Unidos (with Norma Alarcón). San Francisco: Ism Press, 1988. (Spanish adaptation of This Bridge Called My Back: Writings by Radical Women of Color, edited by Cherríe Moraga.)

As editor

• The Sexuality of Latinas (co-editor, with Norma Alarcón and Cherríe Moraga). Berkeley: Third Woman Press, 1993. ISBN 0-943219-00-0
• Goddess of the Americas: Writings on the Virgin of Guadalupe / La Diosa de las Américas: Escritos Sobre la Virgen de Guadalupe (editor). New York: Riverhead Books, 1996. ISBN 1-57322-029-9

as of March 2008:

Journal articles

1. Castillo's 'Burra, Me', 'La Burra Mistakes Friendship with a Lashing', and 'The Friend Comes Back to Teach the Burra' By: Ruiz-Velasco, Chris; Explicator, 2007 Winter; 65 (2): 121-24.
2. 'The Pleas of the Desperate': Collective Agency versus Magical Realism in Ana Castillo's So Far From God By: Caminero-Santangelo, Marta; Tulsa Studies in Women's Literature, 2005 Spring; 24 (1): 81-103.
3. Violence in the Borderlands: Crossing the Home Space in the Novels of Ana Castillo By: Johnson, Kelli Lyon; Frontiers: A Journal of Women Studies, 2004; 25 (1): 39-58.
4. Literary Syncretism in Ana Castillo's So Far From God By: Alarcón, Daniel Cooper; Studies in Latin American Popular Culture, 2004; 23: 145-52.
5. The Second Tower of Babel: Ana Castillo's Borgesian Precursors in The Mixquiahuala Letters By: Jirón-King, Shimberlee; Philological Quarterly, 2003 Fall; 82 (4): 419-40.
6. Creating a Resistant Chicana Aesthetic: The Queer Performativity of Ana Castillo's So Far from God By: Mills, Fiona; CLA Journal, 2003 Mar; 46 (3): 312-36.
7. The Homoerotic Tease and Lesbian Identity in Ana Castillo's Work By: Gómez-Vega, Ibis; Crítica Hispánica, 2003; 25 (1-2): 65-84.
8. Ana Castillo's So Far from God: Intimations of the Absurd By: Manríquez, B. J.; College Literature, 2002 Spring; 29 (2): 37-49.
9. Hybrid Latina Identities: Critical Positioning In-Between Two Cultures By: Mujcinovic, Fatima; Centro de Estudios Puertorriqueños, 2001 Spring; 13 (1): 45-59.
10. Con un pie a cada lado'/With a Foot in Each Place: Mestizaje as Transnational Feminisms in Ana Castillo's So Far from God By: Gillman, Laura; Meridians: Feminism, Race, Transnationalism, 2001; 2 (1): 158-75.
11. La Llorona and a Call for Environmental Justice in the Borderlands: Ana Castillo's So Far from God By: Cook, Barbara J.; Northwest Review, 2001; 39 (2): 124-33.
12. Chicana/o Fiction from Resistance to Contestation: The Role of Creation in Ana Castillo's So Far from God By: Rodriguez, Ralph E.; MELUS, 2000 Summer; 25 (2): 63-82.
13. Rebellion and Tradition in Ana Castillo's So Far from God and Sylvia López-Medina's Cantora By: Sirias, Silvio; MELUS, 2000 Summer; 25 (2): 83-100.
14. Gritos desde la Frontera: Ana Castillo, Sandra Cisneros, and Postmodernism By: Mermann-Jozwiak, Elisabeth; MELUS, 2000 Summer; 25 (2): 101-18.
15. Chicana Feminist Narratives and the Politics of the Self By: Elenes, C. Alejandra; Frontiers: A Journal of Women Studies, 2000; 21 (3): 105-23.
16. 'Saint-Making' in Ana Castillo's So Far from God: Medieval Mysticism as Precedent for an Authoritative Chicana Spirituality By: Sauer, Michelle M.; Mester, 2000; 29: 72-91.

Book articles/chapters

1. Determined to Indeterminacy: Pan-American and European Dimensions of the Mestizaje Concept in Ana Castillo's Sapogonia By: Köhler, Angelika. IN: Bottalico and Moncef bin Khalifa, Borderline Identities in Chicano Culture. Venice, Italy: Mazzanti; 2006. pp. 101—14
2. Ana Castillo (1953-) By: Castillo, Debra A.. IN: West-Durán, Herrera-Sobek and Salgado, Latino and Latina Writers, I: Introductory Essays, Chicano and Chicana Authors; II: Cuban and Cuban American Authors, Dominican and Other Authors, Puerto Rican Authors. New York, NY: Scribner's; 2004. pp. 173—93
3. The Spirit of a People: The Politicization of Spirituality in Julia Alvarez's In the Time of the Butterflies, Ntozake Shange's sassafrass, cypress & indigo, and Ana Castillo's So Far from God By: Blackford, Holly. IN: Groover, Things of the Spirit: Women Writers Constructing Spirituality. Notre Dame, IN: U of Notre Dame P; 2004. pp. 224—55
4. 'A Question of Faith': An Interview with Ana Castillo By: Kracht, Katharine. IN: Alonso Gallo, Voces de América/American Voices: Entrevistas a escritores americanos/Interviews with American Writers. Cádiz, Spain: Aduana Vieja; 2004. pp. 623—38
5. A Chicana Hagiography for the Twenty-first Century By: Alcalá, Rita Cano. IN: Gaspar de Alba, Velvet Barrios: Popular Culture & Chicana/o Sexualities. New York, NY: Palgrave Macmillan; 2003. pp. 3—15
6. Ana Castillo as Santera: Reconstructing Popular Religious Praxis By: Pérez, Gail. IN: Pilar Aquino, Machado and Rodríguez, A Reader in Latina Feminist Theology: Religion and Justice. Austin, TX: U of Texas P; 2002. pp. 53—79
7. A Two-Headed Freak and a Bad Wife Search for Home: Border Crossing in Nisei Daughter and The Mixquiahuala Letters By: Cooper, Janet. IN: Benito and Manzanas, Literature and Ethnicity in the Cultural Borderlands. Amsterdam, Netherlands: Rodopi; 2002. pp. 159—73

Books

1. New Visions of Community in Contemporary American Fiction: Tan, Kingsolver, Castillo, Morrison By: Michael, Magali Cornier. Iowa City: U of Iowa P; 2006.
2. Exploding the Western: Myths of Empire on the Postmodern Frontier By: Spurgeon, Sara L.. College Station, TX: Texas A&M UP; 2005.
3. Ana Castillo By: Spurgeon, Sara L.. Boise: Boise State U; 2004.