Close was born on March 19, 1947 in Greenwich, Connecticut, to william Taliaferro Close, a Doctor who operated a clinic in the Belgian Congo and served as a personal physician to Zaire's ruler Mobutu Sese Seko, and socialite Bettine Moore Close. She has two sisters, Tina and Jessie, and two brothers, Alexander (nicknamed Sandy) and Tambu Misoki, whom Close's parents adopted while living in Africa.

Close has been married four times, each ending in divorce. Her first marriage ended before going off to university. Close described it as "kind of an arranged marriage." From 1969 to 1971, Close was married to Cabot Wade, a Guitarist and Songwriter, with whom she had performed during her time at Up with People. She was married to businessman James Marlas from 1984 to 1987. Soon afterwards, she began a relationship with Producer John Starke, whom she had previously met on the set of The World According to Garp. Their daughter, Annie Starke, was born in 1988 and is an Actress. They separated in 1991. In 1995 Close was engaged to carpenter Steve Beers, who had worked on Sunset Boulevard, but the two never married, and they separated in 1999. In February 2006, Close married executive and venture capitalist David Evans Shaw in Maine. The couple divorced in August 2015.

Close has had an extensive career performing in Broadway musicals. She began performing in 1974, and received her first Tony Award nomination in 1980 for Barnum. One of her most notable roles on stage was Norma Desmond in the Andrew Lloyd Webber production of Sunset Boulevard, for which Close won a Tony Award, playing the role on Broadway in 1993-94. For her role, Close was met with critical acclaim. David Richards of The New York Times wrote in 1994 that "Glenn is giving one of those legendary performances people will be talking about years from now. The Actress takes breathtaking risks, venturing so far out on a limb at times that you fear it will snap. It doesn't."

Close began to do television movies in the early 1980s beginning with The Elephant Man and in 1984, starred in the critically acclaimed drama Something About Amelia, a Golden Globe-winning television movie about a family destroyed by sexual abuse of the Incest type. (Ted Danson appeared as the abusing husband-father; Roxana Zal acted out the role of Amelia, the daughter-victim of Danson's character, which role first brought Zal to prominence.) She starred alongside Keith Carradine in Stones for Ibarra (1988), a television film adaption from the book written by Harriet Doerr and produced by the Hallmark company.

Her film debut was in The World According to Garp (1982), which she followed up with supporting roles in The Big Chill (1983) and The Natural (1984); all three earned her nominations for the Academy Award for Best Supporting Actress. She would later receive nominations for the Academy Award for Best Actress for her performances in Fatal Attraction (1987), Dangerous Liaisons (1988) and Albert Nobbs (2011). She won two more Tony Awards in the 1990s, for Death and the Maiden in 1992 and Sunset Boulevard in 1995, while she won her first Emmy Award for the 1995 TV film Serving in Silence: The Margarethe Cammermeyer Story.

In 1984 Close was given a part in Robert Redford's baseball drama The Natural, although it was a small supporting role she earned a third consecutive Oscar nomination. Close, to this day, credits her nomination to Cinematographer Caleb Deschanel, stating ''That hat was designed so the sunlight would come through. We waited for a certain time of day, so the sun was shining through the back of the stadium. And he had a lens that muted the people around me. It was an incredibly well thought-out shot. And I honestly think that's the reason I got nominated.'' Close also starred opposite Robert Duvall in the drama The Stone Boy (1984), a film about a family coping after their youngest child accidentally kills his older brother in a hunting accident.

Eventually, Close began to seek different roles to play because she did not want to be typecast as a motherly figure. She starred in the 1985 romantic comedy Maxie, alongside Mandy Patinkin. Close was given favorable reviews and even received her second Golden Globe Award nomination, but the movie was critically panned and under-performed at the box office. In 1985 Close starred in the legal thriller Jagged Edge, opposite Jeff Bridges. Initially, Jane Fonda was attached to the role, but was replaced with Close when she requested changes in the script. Producer Martin Ransohoff was against the casting of Close because he said she was "too ugly" for the part. Close eventually heard about this and said she didn't want Ransohoff on set while she was making her scenes. Director Richard Marquand stood by her side and sent Ransohoff away. Infuriated, Ransohoff went to the studio heads trying to get Close and Marquand fired from the picture. The studio refused, stating they were pleased with their work in the film. Jagged Edge received favorable to positive reviews and grossed $40-million on a $15-million budget.

Close is a New York Mets fan, and has sung the national anthem at Shea Stadium and Citi Field numerous times since 1986.

In 1987 Close played the disturbed book Editor Alex Forrest in Fatal Attraction; this was the role that propelled her into stardom. The movie became a huge box-office success, the highest-grossing film worldwide of that year. The character of Alex Forrest has been considered one of Close's most iconic roles; the phrase "bunny boiler" has even been added to the dictionary, referencing a scene from the movie.

She played a scheming aristocrat, the Marquise de Merteuil, in 1988's Dangerous Liaisons. Close earned stellar reviews for this performance, and was nominated for an Oscar for Best Actress. In addition, she received her first BAFTA nomination but did not win. Close's final film role of the decade was Immediate Family (1989), a drama about a married couple seeking to adopt a child. Producer Lawrence Kasdan had Close star in the film, as he directed her previously in The Big Chill.

Close has campaigned for many issues like gay marriage, women's rights, and mental health. In 1989 she attended pro-choice marches in Washington D.C. with Gloria Steinem and Jane Fonda. In 1998, Close was a part of a star-studded cast which performed The Vagina Monologues at a benefit. It raised $250,000 in a single evening with proceeds going to the effort to stop violence against women. She was honored with a GLAAD Media Award in 2002 for promoting equal rights for lesbian, gay, bisexual and transgender people. She volunteered and produced a documentary for Puppies Behind Bars, an organization that provides Service dogs for wounded war veterans. She is also a trustee of The Wildlife Conservation Society and volunteers at Fountain House in New York City, a facility dedicated to the recovery of men and women who suffer with mental illness. Close is a founding member of the Panthera Conservation Advisory Committee. Panthera is an international nonprofit whose sole mission is conservation of the world's 36 species of wild cats. Close has also been a longtime supporter of late friend Christopher Reeve's foundation. She is also a member of the CuriosityStream Advisory Board.

Close keeps all of her costumes after completing films and rents them out to exhibits. She is a huge Madonna fan, and lent her the dress she wore in Dangerous Liaisons for Madonna's 1990 VMA performance of Vogue. In 2017, she donated her entire costume collection to the Indiana University Bloomington

Close appeared in the newsroom comedy-drama The Paper (1994), directed by her good friend Ron Howard. She would go on to appear in the alien invasion satire Mars Attacks! (1996) as The First Lady and as the sinister Cruella de Vil in the Disney hit 101 Dalmatians. Close's portrayal of Cruella de Vil was universally praised and earned her a Golden Globe nomination for Best Actress in a comedy. The film was also a commercial success, grossing $320.6 million in theaters against a $75 million budget. The following year, Close appeared in another box office hit with Air Force One (1997), playing the trustworthy vice President to Harrison Ford's President. Close would later star in the war film Paradise Road (1997) as a choir Conductor of the women imprisoned by the Japanese in World War II. In 1999, Close provided the voice of Kala in Disney's animated film Tarzan. She later went on to receive great reviews for her comedic role as Camille Dixon in Cookie's Fortune (1999).

Close is the President of Trillium Productions Inc. Her company has produced films like Albert Nobbs, Sarah Plain and Tall, and South Pacific. She also produced the film Serving in Silence (1995) with Barbra Streisand, for which they were both nominated for an Emmy for Outstanding Television Movie. Close's other production credits include Journey (1995), and the upcoming film Cruella (2018), based on the character which Close played in 101 Dalmatians.

Close was also a guest star at the Andrew Lloyd Webber fiftieth birthday party celebration in the Royal Albert Hall in 1998. She would later re-team with the show's Director, Trevor Nunn, in London for his Royal National Theatre revival of A Streetcar Named Desire in 2002. Close won a Tony Award in 1984 for The Real Thing, directed by Mike Nichols. In 1992 she won another Tony Award for Death and the Maiden. In 2008, Close performed at Carnegie Hall, narrating the violin concerto The Runaway Bunny, a concerto for reader, violin and orchestra, composed and conducted by Glen Roven. She provided the voice of the "Giant" in the Summer 2012 production of the musical Into the Woods at the Delacorte Theater in Central Park. The production also featured Amy Adams as The Baker's Wife and Donna Murphy as The Witch. In 2014 she starred in a production of the Pirates of Penzance for the Public Theater in New York, playing the role of Ruth. This production featured Kevin Kline, Martin Short and Anika Noni Rose.

Close began to appear in television movies rather than doing theatrical films in the early 2000s. She returned as Cruella de Vil in 102 Dalmatians (2000), although the film received mixed reviews, it performed well at the box office. Close later filmed The Safety of Objects which premiered in 2001, a movie about four suburban families dealing with maladies. This was Kristen Stewart's first film role, Close and Stewart would later reunite in the 2015 film Anesthesia. Close starred in Things You Can Tell Just by Looking at Her in the same year, this would be one of many Future collaborations with Director Rodrigo Garcia. In 2004, she played Claire Wellington, an uptight socialite in the comedy The Stepford Wives opposite Nicole Kidman and Christopher Walken. She provided the voice of the Blue Fairy in the English version of Pinocchio (2002) and Granny in the animated film Hoodwinked (2005). Close continued to do smaller films like Le Divorce (2003) and The Chumscrubber (2005). In 2005, she reunited with Director Rodrigo Garcia to do Nine Lives; he would later direct Close in the film Albert Nobbs (2011). In the same year, she starred in the film Heights (2005), an independent drama centered on the lives of five New Yorkers. Close's performance was lauded by critics. In 2007, Close joined friend and previous co-star Meryl Streep in the ensemble drama Evening. This would be Close's final theatrical film role of the decade, since she began to star in her own television series, Damages (2007). Close was asked about her contributions to independent films, to which she responded "I love the casts that gather around a good piece of writing certainly not for the money but because it is good and challenging. Sometimes I've taken a role for one scene that I thought was phenomenal. Also my presence can help them get money, so it's I think a way for me to give back."

On method acting, she claims that while she found it an interesting technique, it was not her preferred style. Although Close does extensive research and preparation for her roles, she also relies less on the technicality of a performance saying, "Good acting I think is like being a Magician, in that you make people believe; because it's only when they believe that they are moved. And I want people to get emotionally involved. I think technique is important but it isn't everything. You can have a great technical actor who'll leave people cold. That's not my idea of great acting. As audience, I don't want to be aware of acting." Longtime collaborator and Playwright, Christopher Hampton describes Close an Actress who can very easily convey "a sense of strength and intelligence." Hampton worked on Sunset Boulevard and the stage production of Dangerous Liaisions, Hampton later cast her in the movie version. "Glenn is often described as having a glacial or distant quality about her, but in person she's the absolute opposite: warm and intimate," says the actor Iain Glen, who co-starred with her in the 2002 stage production of A Streetcar Named Desire. "She was able to bring strength to the role, she was able to completely access that vulnerability. There was a real softness to her.

She starred as Eleanor of Aquitaine in the 2003 TV film The Lion in Winter, winning a Golden Globe Award. In 2005 she starred in the drama series The Shield. Then, from 2007 to 2012, she starred as Patty Hewes in the FX drama series Damages, a role that won her a Golden Globe and two Emmys. She has voiced the character of Mona Simpson in the animated sitcom The Simpsons since 1995. She returned to Broadway in November 2014, in a revival of Edward Albee's A Delicate Balance. Her other films include Jagged Edge (1985), Hamlet (1990), Reversal of Fortune (1990), 101 Dalmatians (1996), Paradise Road (1997), Air Force One (1997), Cookie's Fortune (1999), Heights (2005), Guardians of the Galaxy (2014) and The Girl With All The Gifts (2016).

Close was born into a Democratic family. In addition, she has donated money to the election campaigns of mostly Democratic politicians, including Hillary Clinton, Howard Dean, John Edwards, Angus King and Barack Obama. She also spoke at the 2004 Democratic National Convention. Close voted for Barack Obama in the 2008 presidential election and attended his inauguration. In a 2016 interview with Andrew Marr for the BBC, Close criticized Donald Trump, calling his campaign "terribly frightening." She later reiterated her sentiments about Trump, stating, "he doesn’t stand for anything I believe in."

In 2007 she co-founded FetchDog, a dog accessories catalog and Internet site. She published blogs where she interviews other celebrities about their relationships with their dogs. She sold the Business in 2012.

On January 12, 2009, Close was honored with a star on the Hollywood Walk of Fame at 7000 Hollywood Boulevard, in front of the Roosevelt Hotel. As of 2017, films featuring Close have grossed over $1.3 Billion in North America. She is also a member of the Academy of Motion Picture Arts and Sciences. Close is also considered a gay icon, having played numerous campy roles on screen and stage.

In December 2010, Close began filming Albert Nobbs in Dublin. She had previously won an Obie in 1982 for her role in the play on stage. She had been working on the film, in which she appeared alongside 101 Dalmatians co-star Mark Williams, for almost 20 years, and aside from starring in it, she co-wrote the screenplay, and produced the film. Close expressed that it became more important for her to make this film to stimulate conversations about transgender issues, "There came a point where I asked, 'Am I willing to live the rest of my life having given up on this?' And I said, 'No I won't.' Some people will change their point of view, and those who are either too old, or too blinkered, to accept the beauty of difference will just have to 'die off'." In the film, Close played the title role of Albert Nobbs, a woman living her life as a man in 1800s Ireland after being sexually assaulted as a young girl. While the film itself received mixed reviews, Close and Janet McTeer received rave reviews for their performances. Close's performance was noted for being her most subtle and introverted performance yet and a departure from her other roles. She received Academy Award, Golden Globe, Screen Actors Guild, and multiple critics nominations for her performance. Close was asked about the fact of not having an Oscar during the film's awards campaign, for which she answered: "And I remember being astounded that I met some people who were really kind of almost hyper-ventilating as to whether they were going to win or not, and I have never understood that. Because if you just do the simple math, the amount of people who are in our two unions, the amount of people who in our profession are out of work at any given time, the amount of movies that are made every year, and then you're one of five. How could you possibly think of yourself as a loser?"

Along with Viola Davis and Uma Thurman, Close was featured in the 2012 documentary Love, Marilyn, reading excerpts from Marilyn Monroe's diaries. Critic Stephen Farber has described the film as "One of the most skillful and entertaining summaries of Marilyn's endlessly fascinating rise and fall." After her television series Damages ended, Close returned to film in 2014, in which she played Nova Prime Rael in the science fiction film Guardians of the Galaxy. Close also appeared in the independent movie 5 to 7 (2014) and Low Down (2014). In 2016, she appeared in The Great Gilly Hopkins and Warcraft. She also starred in the British zombie horror drama The Girl with All the Gifts (2016) as Dr. Caldwell, a scientist researching a cure to save humanity.

However, Close is consistently praised for her roles as the villain or antagonist in her performances. Her character in Fatal Attraction was ranked #7 on AFI's 100 years...100 heroes and villains list. Regarding her role in the series Damages, The New York Times remarked "There is no actor dead or alive as scary as a smiling Glenn Close." Journalist Christopher Hooton also praised her saying, "Christopher Walken, Glenn Close, Al Pacino, and many others have a surprising danger in them. They're a little scary to be around, because you feel they might jump you or blow up at you at any time. They are ticking time bombs." Film Historian Cari Beauchamp has stated, "When you look at the top 10 actresses of the past 80 years, since sound came in, first you have Bette Davis, Katharine Hepburn and Meryl Streep – but I think Glenn Close is definitely in that list, it's a combination of her guts, in the roles she chooses, and her perseverance. Frankly, she's taken roles that are more challenging than a lot of other people."

In October 2014, Close returned to Broadway in the starring role of Agnes in Pam MacKinnon's revival of Edward Albee's A Delicate Balance at the Golden Theatre. Her co-stars were John Lithgow as Tobias, Martha Plimpton as Julia and Lindsay Duncan as Claire. The production grossed $884,596 over eight preview performances during the week ending Oct. 25, setting a new house record at the Golden Theatre. The production received mixed reviews, although the cast was praised.

Close was a founder and is chairperson of BringChange2Mind, a US campaign to eradicate the stigma and discrimination surrounding mental illness, supporting her sister Jessie who has bipolar disorder. In 2010, Close announced to the public that she had her DNA sequenced in order to publicize her family's history of mental illness. During the month of July 2013, Close put up over 380 designer items up for auction on eBay from the wardrobe her character Patty Hewes wore on Damages. All proceeds were raised to go to her charity BringChange2Mind. Close had Director and friend Ron Howard direct the foundation's first PSA. John Mayer also lent his song "Say" for the advert. In 2013 Close went to the White House to urge passage of the Excellence in Mental-Health Act that was written to expand treatment for the mentally ill and to provide access to mental-health services. The bill was signed into law by President Obama in April 2014, and will provide $1.1 billion in funding to help strengthen the mental-health-care system in the US. She was awarded the WebMD Health Hero award in 2015 for her contributions to mental-health initiatives. On June 16, 2016, Close donated $75,000 to the Mental-Health Association of Central Florida in order to fund counselling and other assistance to victims of the Orlando nightclub shooting. She frequently promotes her charitable causes through her Twitter account.

In April 2016 she returned as Norma Desmond in the musical Sunset Boulevard in an English National Opera production in the West End in London. Close was met with rave reviews after returning to this same role twenty-three years later. Both The Times and The Daily Telegraph gave the production five stars and praised her performance. During the production Close was forced to cancel three shows due to a chest infection. She was hospitalized but later recovered and finished the remaining shows. Close won the Evening Standard Theatre Award for Best Musical Performance, and was nominated for her first Olivier Award for Best Actress in a Musical. The ENO London production of Sunset Boulevard transferred to the Palace Theatre on Broadway, with Close reprising her role. It opened on February 9, 2017 in a limited run, selling tickets through June 25, 2017. The production features a 40-piece orchestra, the largest in Broadway history. Close in particular was lauded by critics for her new incarnation of Norma Desmond. As The New York Times called it "one of the great stage performances of this century." Variety, Parade, The Guardian and Entertainment Weekly also gave the new production positive reviews.

When she was seven years old, her parents joined the Moral Re-Armament (MRA), in which her family remained involved for fifteen years, living in communal centers. Close described MRA as a "cult" that dictated every aspect of her life, from the clothes that had to be worn to what she was allowed to say. In an interview Close stated that her Desire to become an Actress allowed her to break away from MRA, stating: "I have long forgiven my parents for any of this. They had their reasons for doing what they did, and I understand them. It had terrible effects on their kids, but that’s the way it is. We all try to survive, right? And I think what actually saved me more than anything was my Desire to be an Actress." She spent time in Switzerland when studying at St. George's School in Switzerland. Close traveled for several years in the mid-to-late 1960s with an MRA singing group called Up With People, and attended Rosemary Hall (now Choate Rosemary Hall), graduating in 1965. During her time in Up With People, Close organized a small singing group, the Green Glenn Singers, consisting of herself, Kathe Green, Jennie Dorn, and Vee Entwistle. The group's stated mission was "to write and sing songs which would give people a purpose and inspire them to live the way they were meant to live."