Ai was born Florence Anthony on October 21, 1947, in Albany, Texas. Her father was Japanese, and her mother (who was not married to him) was a mixture of Choctaw Indian, southern Cheyenne, African American, Dutch, and Irish. Ai was raised as a Catholic by her mother, and she and her halfsister attended Catholic school until seventh grade. She recalls that when she was a child, her family was very poor, and her stepfather, Sutton Haynes, needed to borrow money so he could buy food for the family. After living for a period in San Francisco and Los Angeles, the family moved to Tucson, Arizona, in 1961, when Ai was fourteen. By that age, she had discovered through a poetry competition at school that she could write poetry. Her earliest poems were all imitations of Edgar Allen Poe, to whose work she had been introduced at school.
After graduating from high school, Ai attended the University of Arizona, where she continued to write poetry. It was there that she changed her name to Ai, which is the Japanese word for love. It was also at the University of Arizona that she met the poet Galway Kinnell, when he gave a reading. Ai sent some of her poems to Kinnell for his comments, and he encouraged her to apply to the writing program at the University of California at Irvine. After graduating in 1969, with a bachelor of arts degree in Japanese language and literature, Ai did indeed go on to graduate school at Irvine. It was during her graduate career that she decided that she wanted to write in the language of the common person, and her goal was to make her work as accessible as possible. She received a master of fine arts degree from the University of California, Irvine, in 1971. During her second year at Irvine, Kinnell showed her poems to an editor at Houghton Mifflin, and the result was her first book, Cruelty, published in 1973.
Recognition for Ai’s work came quickly. She was a Guggenheim fellow in 1975, and a Radcliffe (now Bunting) Institute fellow in the same year. She was awarded a Massachusetts Arts and Humanities fellowship in 1976, and was visiting poet at Wayne State University 1977–1978. A second volume of poems, Killing Floor, followed in 1979. This volume was chosen as the 1978 Lamont Poetry Selection of the Academy of American Poets.
Ai’s third collection of poems was Sin (1986), which won the American Book Award, and this was followed by a fourth collection, Fate, in 1991. In 1993, her fifth collection, Greed, was published by Norton, as was Vice: New and Selected Poems, in 1999. Vice was a collection of previous work along with seventeen new poems, and it won the 1999 National Book Award for Poetry.
Ai was writer-in-residence at Arizona State University from 1988 to 1989, and visiting associate professor, 1996–1997, at the University of Colorado at Boulder. In 1999, she became a tenured professor at Oklahoma State University.