Maripat Donovan was born in Chicago, attended Catholic grammar school and high school on the South Side of Chicago, and Loyola University on the city's North Side.

After working in both her high school and college theater departments, often building and designing sets, she developed her own construction company and renovated houses for a number of years.

In 1985, she returned to theater as an understudy in Portrait of a Shiksa, a role for which she earned a Jeff Citation for Best Supporting Actress. She earned another Jeff Citation for her work in the ensemble of The Good Times Are Killing Me.

In 1993, Maripat created Late Nite Catechism with her writing partner, Vicki Quade. She also originated the role of Sister in Late Nite Catechism and has been the star of virtually every production in the United States, London, Dublin and in Toronto.