Clarkson raised in New Orleans, LA where her mother was a local politician and her father was an administrator at Louisiana State University. The youngest of five daughters, Clarkson was serious about becoming an actress from the time she was a teenager and joined up with a very progressive, nurturing high school theater club. She studied speech pathology at LSU before transferring to Fordham University's College at Lincoln Center, where she earned a Bachelors Degree in Theater Arts. In 1985, with a MFA from the esteemed Yale School of Drama, Clarkson made her professional stage debut in New York in "Oliver, Oliver." While her stage career took off immediately, her film career had a promising start with a supporting role as the sweet young wife of G-man Eliot Ness (Kevin Costner) in Brian De Palma's "The Untouchables" (1987), a summer blockbuster that helped boost the strawberry blonde's visibility. The relative newcomer scored again with a great performance as the fast-talking television journalist opposite Clint Eastwood in the Dirty Harry finale "The Dead Pool" (1988). She immediately began to prove her mettle with supporting appearances as Burt Lancaster's daughter in "Rocket Gibraltar" (1988), the story of an eccentric wealthy family as well as in "Everybody's All American" (1988), a period drama set in the South. Her delicate patrician looks continued to snare Clarkson further roles as mild, post-war type moms in the 1950s-set comedy "Tune in Tomorrow" (1990) and a television adaptation of Hemingway's "The Old Man and the Sea" (NBC, 1990) starring Anthony Quinn. While her film career appeared to stall temporarily, Clarkson spent the early 1990s with a recurring stint on the short-lived Randy Quaid/Jonathan Winters' sitcom, "Davis Rules" (ABC, 1991) and a run of television movies including Alex Haley's "Queen" (CBS, 1993). In another steady primetime outlet, Clarkson played Ted Hoffman's patient wife on the captivating drama series, "Murder One" (ABC, 1995-96) before co-starring alongside Kris Kristofferson and Chris Cooper in "Pharaoh's Army" (PBS, 1995), where she gave an excellent dramatic turn as a Confederate woman forced to give shelter to a contingent of Union soldiers. Clarkson had a starring role in an NBC television adaptation of Neil Simon's "London Suite" (NBC, 1996) and revisited the stage in New York productions "Raised in Captivity" and "Three Days of Rain" before her film career again picked up momentum. Following a role in the ensemble cast of the comic drama "Playing By Heart" (1998), she gave one of the best screen performances of her career in Lisa Cholodenko's independent film "High Art" (1998), starring as a washed-up, drug-addicted German actress and lover of a reclusive photographer (Ally Sheedy). The film marked a turning point in Clarkson's career, in that it showcased her in a new light and gave filmmakers a glimpse of her untapped versatility and edge. Later that year, she won a Best Supporting Actress from the Saturn Awards for her turn as a prison warden's wife in Frank Darabont's adaptation of Stephen King's "The Green Mile" (1999). Her recent screen achievements helped transform the actress into a favorite on the independent film scene, so it was in rapid succession that she landed supporting roles in Stanley Tucci's well-received portrait of 1940s Greenwich Village "Joe Gould's Secret" (2000) and Rose Troche's "The Safety of Objects" (2001), playing a financially struggling suburban mom of two in the film adaptation of A.M. Holmes' darkly satiric collection of short stories.The lighthearted heist comedy "Welcome to Collinwood" (2002) opened to a warm reception at the Cannes Film Festival though Clarkson made a stronger critical impression in Todd Haynes' "Far From Heaven" (2002). For her supporting role as the closest friend of a woman (Julianne Moore) in 1950s Connecticut whose idyllic life is shattered when she learns that her husband is having a gay affair, Clarkson was recognized with a New York Film Critics Circle Award, National Society of Film Critic's Award, and Chlotrudis Award. The same year, the steadily rising actress won an Emmy Award for Outstanding Guest Actress in a Drama Series for her recurring role as the free-spirited Sarah on the HBO hit series "Six Feet Under" (HBO, 2001-05). The wave of critical recognition was still going strong in 2003, with Clarkson appearing in three films screened at the Sundance Film Festival. In a leading role, she played a mourning mother who forms a unique bond with a train-obsessed dwarf (Peter Dinklage) in "The Station Agent," earning an Outstanding Performance by a Female Actor nod from the Screen Actor's Guild. She also essayed a single mom who supports herself as a clown-for-hire in the coming-of-age drama "All The Real Girls" (2002) and capped off the year with a stellar performance as the hyper-critical, terminally ill mother who will do anything to avoid Thanksgiving dinner at the apartment of her disappointing eldest daughter April (Katie Holmes) in "Pieces of April" (2003). The slew of winning performances earned Clarkson a Special Jury Award at Sundance and "Pieces" garnered the actress her first Supporting Actress nomination from both the Academy and the Golden Globes.Taking a break from the whirlwind couple years onscreen, Clarkson took on the coveted role of Blanche DuBois in a Washington D.C. production of "A Streetcar Named Desire" in 2004 and made her next impression in Craig Lucas' satirical and provocative Hollywood-set indie "The Dying Gaul" (2004). She followed up with a nicely etched supporting turn in George Clooney's second directorial effort "Good Night and Good Luck" (2005), evidencing warm chemistry with Robert Downey, Jr. as a pair of broadcast journalists on Edward R. Murrow's news team who try to keep their marriage a secret. Clarkson was a natural casting choice for Steve Zaillian's film adaptation of Robert Penn Warren's tale of a corrupt 1940s New Orleans politician in "All The King's Men" (2006) which unfortunately met with critical backlash, though the actress rebounded with a second Emmy Award for her continuing guest appearances on "Six Feet Under." In 2007, she had a supporting role in the successful box office romance "No Reservations" (2007) and played a doctor whose patient is having a relationship with a life-sized, mail-order doll in the charming indie hit, "Lars and the Real Girl" (2007). Actor-director Stanley Tucci tapped Clarkson to play opposite him as grieving parents in "Blind Date" (2008), after which she played opposite Chris Cooper as a restricted 1940s housewife whose seemingly perfect marriage to a successful corporate exec is not all that it seems in the limited release, "Married Life" (2008). Clarkson enjoyed a pivotal supporting role in Woody Allen's acclaimed "Vicky Cristina Barcelona" (2008), following up that high profile offering with a wonderful performance as the supportive drama teacher of a gifted but emotionally troubled girl (Elle Fanning) in "Phoebe in Wonderland" (2009). She teamed with Allen again in the filmmaker's return to New York-set films, "Whatever Works" (2009), and delivered a critically hailed performance as a magazine editor who has an affair with an Egyptian man (Alexander Siddig) in the Canadian-made romantic drama "Cairo Time" (2009). From there, Clarkson was the second Rachel Solando - the first played by Emily Mortimer - in Martin Scorsese's psychological thriller "Shutter Island" (2010), starring Leonardo DiCaprio as a U.S. Marshal investigating the disappearance of a mental institution patient. She next played the resistant mother of a book-smart teen (Devon Graye) who joins his high school's wrestling team in order to reunite with his estranged brother (John Cena) in the small sports-themed drama "Legendary" (2010). After a turn in the near-universally panned ensemble drama "Main Street" (2010), Clarkson was memorable as the open-minded mother of a rumor-plagued teen (Emma Stone) in the surprise hit indie comedy "Easy A" (2010). Meanwhile, she was the mother of a young professional (Mila Kunis) in a no-strings-attached affair with a client (Justin Timberlake) in "Friends with Benefits" (2011), and returned to television with a guest turn as the first wife of Ron Swanson (Nick Offerman) on a fourth season episode of "Parks and Recreation" (NBC, 2009-15). Her big screen career continued with supporting roles in the thriller "The East" (2013), romantic drama "Learning To Drive" (2014), and dystopian science fiction adaptation "The Maze Runner" (2014) and its sequel "he Maze Runner: The Scorch Trials" (2015). She also starred in the indie drama "Last Weekend" (2014).