Ms. Ligon was born into the business. She was the child of actor David Clarke (the original Broadway productions of The Visit and Orpheus Descending) and dialect coach Nora Dunfee. Her first Broadway job was the 1990 Circle in the Square revival of The Miser. She worked on the celebrated 1993 revival of She Loves Me; the 1994 Mercedes Ruehl production of The Rose Tattoo; the Billy Crudup-Mary-Louise Parker revival of Bus Stop in 1996; as well as Broadway productions of Garden District, Tartuffe, 1776 and the musical premiere Steel Pier. She often worked with Circle in the Square and the Roundabout Theatre Company.
She was born Katharine Dunfee Clarke and made her only Broadway acting appearance in Under Milkwood at the age of eight.
She taught at City U. of New York, NYU Tisch School of the Arts and the New Actors Workshop. She is survived by her husband, actor Tom Ligon, and a sister, Susan Dunfee.