The actress will play a former corporate secretary called Carol Miller in the show, TV Guide reports.
Carol has been living on a remote farm in Wisconsin, but as her history is unravelled she begins to show her tough side.
Harper has previously appeared in shows including Crash, Breaking Bad, Private Practice and Grey's Anatomy.
She was nominated for an Oscar for her role in Crimes of the Heart and also appeared in the movie No Country For Old Men.
Revenge airs on Wednesdays on ABC.
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