Usmagazine.com said Winfrey made the revelation to the movie's star Meryl Streep, who appeared via Skype satellite on the episode of "The Oprah Winfrey Show" that aired Tuesday.
Winfrey said she wanted to play the role of Mrs. Miller, which eventually went to Viola Davis, because she felt a connection to the character and wanted to share some screen time with Streep.
"Doubt," which is based on Shanley's celebrated stage play, is set at a Catholic school and church in the Bronx, circa 1964. Mrs. Miller is the mother of the school's first African-American student, a young boy who may have been molested by a priest, played by Philip Seymour Hoffman. Streep plays a traditional nun who is suspicious of the priest and the modern ideas he wants to introduce in the parish.
Davis earned Golden Globe and Screen Actors Guild nominations for her performance.
Usmagazine.com said Streep appeared surprised to hear Winfrey coveted a co-starring role in her film.