Born Kathleen Ann Bishop, she married photographer and filmmaker Henry Chalfant in 1966. Together they had a son, David Chalfant, who played bass for folk-rock act The Nields, and a daughter, Andromache Chalfant, who followed her mother into the world of theater as a set designer. Kathleen Chalfant studied with Wyn Handman (Artistic Director of The American Place Theatre in New York), which gave her a firm footing in the world of theater. Her first major role was the title character in the classical revival "Eurydice" at The Cubiculo in New York City in 1972. She continued to work consistently on the stage, primarily in New York, through the 1970s and 80s. Chalfant starred in the stage production of Jules Feiffer's "Hold Me" in 1977, and her debut television appearance was in Showtime's 1981 TV adaptation. Her first film role came several years later in Jodie Foster drama "Five Corners" (1987). This led to more regular film work, in films including "Miss Firecracker" (1989), "Out of the Rain" (1991) and Tim Robbins' political satire "Bob Roberts" (1992). Some actors saw theater as a stepping stone to film and television work but for Chalfant, theater was her first love and she always split her time between stage and screen. In 1993, Chalfant was nominated for a Tony for Best Actress for her role in the original Broadway production of Tony Kushner's epic "Angels in America," playing the role that would be taken by Meryl Streep in HBO's 2003 TV adaptation. In 1997, she took on the lead as Vivian Bearing in Margaret Edson's "Wit." The play followed Bearing as she struggled with terminal ovarian cancer. Chalfant shaved her head for the role, but what made her portrayal really strike home was that at the same time Chalfant's own half-brother, Alan Palmer, was also battling cancer. He lived with Chalfant for the last two years of his life and died in 1998. The level of emotion she brought to the part won several awards for her performance, including the Obie, Drama Desk, Lucille Lortel and Outer Circle Critics awards. Perhaps unsurprisingly this acclaim helped her land even larger roles in film and television. 1999 saw Chalfant star in the miniseries "Storm of the Century," written specifically for television by Stephen King, while she was a series regular on procedural drama "The Guardian" (CBS 2001-04). Even with all this film and TV work she never neglected her stage career; 2003 saw her win another Obie for her performance in Alan Bennett's "Talking Heads" in New York. More TV work followed. Like most New York-based actors, Chalfant appeared multiple times on the "Law & Order" franchise, where she played five different characters on the original series (NBC 1990-2010), "Law & Order: Special Victims Unit" (NBC 1999-) and "Law & Order: Criminal Intent" (NBC 2001-2011). She also had a recurring role on Denis Leary's black-humored firefighter drama "Rescue Me" and appeared opposite Kevin Spacey in Netflix's original series, an adaptation of the British political drama "House of Cards".