Martindale was born in Jacksonville, TX, where she grew up. She became a popular student at Jacksonville High, a member of the cheerleading squad, and winner of sundry adolescent laurels, such as the school's Football Sweetheart crown. She attended the local community college, Lon Morris College, gravitating to its theater arts department before later transferring her thespian studies to the University of Michigan in Ann Arbor. Graduating in 1974 with a Bachelor of Arts degree, she traveled the well-worn path to New York City in pursuit of stage work. Martindale struggled for a number of years; her most prominent job by the late-1970s was a recurring stint in Downy fabric softener commercials. In 1984, she won a role in Beth Henley's well-reviewed off-Broadway play "The Miss Firecracker Contest," co-starring Holly Hunter, who would reprise the title character in the 1989 film adaptation. Martindale married musician William Boals in 1986. A year later, she landed a slot in another portentous, Southern-set off-Broadway production, the original staging of "Steel Magnolias" at the WPA Theatre, which saw her as the proprietor of the beauty shop where the main characters congregate. The play proved a hit and garnered her some attention from Hollywood casting agents.Seeking to find steadier work in television, Martindale moved to Los Angeles. She won small parts in telefilms such as "The Child Saver" (NBC, 1988) and CBS' epic miniseries "Lonesome Dove" (1989), as well as her first feature supporting parts in the NASCAR-themed Tom Cruise vehicle "Days of Thunder" (1990) and the Disney box office bomb "The Rocketeer" (1991). In 1992, she would establish a precedent with "Lorenzo's Oil," the story of a couple (Susan Sarandon and Nick Nolte) who take medical research into their own hands when their son develops a disease so rare that doctors have few answers. Martindale delivered a mesmerizing performance as a woman dutifully caring for a similarly afflicted son. Her capacity to render earthy yet ruggedly unflappable practitioners of tough love would make her a much in-demand actress for featured character roles - that of nurses, social workers, shrinks, nuns, maternally inclined co-workers - in such films as "Sabrina" (1995), "Marvin's Room" (1996), "Ghosts of Mississippi" (1996), "Practical Magic" (1998), "In Dreams" (1999), "Ride with the Devil" (1999), "28 Days" (2000) and "The Human Stain" (2003). She also showed a touch for less-than-sympathetic characters, playing a dogmatic Bible-thumper in Sidney Lumet's "Critical Care" (1997) and a corrupt parole officer in the Paul Newman-Gene Hackman-Susan Sarandon thriller, "Twilight" (1998). Though Martindale had made occasional television guest appearances, she landed her first regular series job courtesy of Lumet, who in 2001 cast her as the no-nonsense supervisor of a dysfunctional staff of young public defenders on his A&E series "100 Centre Street." In 2003, she made her Broadway debut in a revival of Tennessee Williams' "Cat on a Hot Tin Roof" co-starring Ashley Judd and Ned Beatty, for which she earned a Tony nomination the next year for her turn as Big Mama. She continued her supporting feature work apace, most notably playing the money-grubbing redneck mom of female boxer Hillary Swank in Clint Eastwood's Oscar-winning picture "Million Dollar Baby" (2004), but she increasingly found work in television. She appeared in two high-profile HBO films: "The Laramie Project" (2002) and "Iron Jawed Angels" (2004), as well as took recurring roles on the CBS supernatural series "Medium" and the Showtime drama "Dexter;" the latter as a chronically ill woman eventually euthanized by the title serial killer. Martindale landed her first lead in Alexander Payne's short film "14th Arrondissement," part of the anthology "Paris, Je T'Aime" (2006), in which she wowed critics as a sweetly clueless American tourist.In 2007, she scored another lead role on the FX series "The Riches," playing the pill-popping next-door neighbor to a con man and his family setting up shop in suburban Texas. She kept it light as the dotty mom of buffoonish country singer Dewey Cox (John. C. Reilly) in "Walk Hard: The Dewey Cox Story" (2007). Near decade's end found Martindale cast in a variety of genres and mediums, playing Miley Cyrus' grandmother in the Disney flick "Hannah Montana: The Movie" (2009), braving juvenile horror in "Orphan" (2009), taking on series TV again on the NBC medical drama "Mercy" (2009-2010), and returning to Disney for its glossy horse-racing picture "Secretariat" (2010). That same year, she landed on another of FX's creator-driven series, "Justified." Joining the second season of the show revolving around lawman protagonist Raylan Givens (Timothy Olyphant), Martindale played Mags Bennet, the matriarchal operator of a rural Kentucky dry-goods store, who also brews moonshine and runs her clan's pot cartel. Her deft touch in balancing Mags' kindly provincial pragmatism with a draconian business sense garnered her a flurry of awards buzz, which materialized in 2011 when she received an Emmy for Outstanding Supporting Actress in a Drama Series. Suddenly a draw, Martindale began working regularly on TV dramas, including recurring roles on the romantic ghost story "A Gifted Man" (CBS 2011-12) and Cold War espionage thriller "The Americans" (FX 2013-). She then co-starred on "The Millers" (CBS 2013-14), a sitcom by Greg Garcia in which she starred as the recently-divorced mother of a local news reporter (Will Arnett), living with her son after her husband (Beau Bridges) walks out on her. The series suffered from poor reviews and middling ratings and was canceled partway through its second season.