Diane O'Leary painted to find evidence of what transpired on this planet during her given era. She attended Texas Christian University, Bacone College, Harvard and Stanford, but never took a course in art. Her graduate degrees are in Southwestern archeology and in Baroque Literature (music).

O'Leary started her artistic career in 1967 and studied with Eric Gibbard and Georgia O'Keefe. Today her paintings are in most of the public and private collections of American Indian art.

Public collections including Diane O'Leary's work are: Berne Museum in Berne, Switzerland; the Denver Art Museum in Colorado; the Solomon Guggenheim Museum in New York; the Heard Museum in Phoenix, Arizona; the Museum of American Indian, Heye Foundation in New York; the Mitchell Indian Museum at Kendall College in Evanston, Illinois; the Millicent Rogers Foundation Museum in Taos. New Mexico; the Philbrook Art Center in Tulsa, Oklahoma; the Peabody Museum at Harvard University in Cambridge, Massachusetts; Stanford University in California and the Wheelwright Museum of the American Indian in Santa Fe, New Mexico.

In recent years O'Leary has largely focused on making quilts which at times relate well to her style of painting. Though mostly abstract, the quilts are all
hand stitched with care and a fabulous sense of design. Loon Quilt produced in 1996 is featured on page 90 of a fine publication To Honor and Comfort Native Quilting Traditions (1997).