Ana Castillo is a poet, novelist, writer, editor, playwright, translator, and scholar. She is known for exploring the Chicana experience with her experimental style. She is also a visual artist who paints and draws.

Her first book, The Mixquiahuala Letters (1986), won the 1987 American Book Award. Her novels Sapogonia and So Far From God were named New York Times Notable Books of the Year in 1990 and 1993, respectively. She has also earned the Carl Sandburg Prize, the Fuller Award for lifetime achievement from the Chicago Literary Hall of Fame, and many other honors.

Castillo writes about Chicana feminism, which she refers to as "Xicanisma", and her work centers on issues of identity, racism, and classism.

Castillo is openly bi and wrote about her bisexuality in her 2016 memoir Black Dove: Mama, Mi'jo, and Me.