Tyler was born Liv Rundgren on July 1, 1977, in New York City at Mount Sinai Hospital in East Harlem. She is the only daughter of Bebe Buell, a model, singer, and former Playboy Playmate (Miss November 1974), and Steven Tyler, the lead singer of Aerosmith. Her mother named her after Norwegian actress Liv Ullmann, after seeing Ullmann on the cover of the March 5, 1977, issue of TV Guide. Her ancestry includes Italian (from her great-grandfather), German, Polish, and English. Tyler has three half-siblings: Mia Tyler (born 1978), Chelsea Anna Tyler Foster née Tallarico (born 1989), and Taj Monroe Tallarico (born 1991). Her maternal grandmother, Dorothea Johnson, founded the Protocol School of Washington.

At age 10 or 11, Liv met Steven Tyler and suspected he was her father. When she asked her mother, the secret was revealed. The truth about Tyler’s paternity did not become public until 1991, when she changed her surname from Rundgren to Tyler, but kept Rundgren as a middle name. Buell’s stated reason for claiming that Rundgren was Liv’s father was that Steven Tyler was too heavily addicted to drugs at the time of Liv’s birth. Since learning the truth about her paternity, Liv and Steven have developed a close relationship. They also have worked together professionally, once when she appeared in Aerosmith’s music video for “Crazy” in 1993, and again when Aerosmith performed songs in the film Armageddon (1998), in which Liv Tyler starred.

Tyler made her feature film debut in Silent Fall in 1994, where she played the elder sister of a boy with autism. In 1995, she starred in the comedy-drama Empire Records. Tyler has described Empire Records as “one of the best experiences” she has ever had. Soon after, she landed a supporting role in James Mangold’s 1995 drama Heavy as Callie, a naive young waitress. The film received favorable reviews; critic Janet Maslin noted: “Ms. Tyler … gives a charmingly ingenuous performance, betraying no self-consciousness about her lush good looks.”

Tyler attended the Congressional Schools of Virginia, Breakwater School, and Waynflete School in Portland, Maine, before returning to New York City with her mother at age 12. She went to York Preparatory in New York City for junior high and high school after her mother researched the school to accommodate Tyler’s ADHD. She also attended the Crossroads School for Arts & Sciences in Santa Monica, California. She graduated from York in 1995 and left to continue her acting career. When asked about her youth, Tyler said: “For me, I didn’t get much of a childhood in my teen years because I’ve been working since I was 14. But that also kept me out of trouble. When everybody was doing acid and partying like crazy, I was at work on a movie in Tuscany … having my own fun, of course, but it was a different kind of thing. I have no regrets. I love the way my life has gone.”

She later appeared in That Thing You Do! (1996), a movie about a fictional one-hit wonder rock band called The Wonders, following their whirlwind rise to the top of the pop charts and, just as quickly, their plunge back to obscurity. The film was written and directed by Tom Hanks. It grossed over $25 million worldwide, and received favorable reviews. In 1997, she appeared in Inventing the Abbotts as the daughter of Will Patton and Barbara Williams’ characters. The movie is based on a short story by Sue Miller. Entertainment Weekly declared Tyler’s performance as “lovely and pliant”. That same year, Tyler was chosen by People magazine as one of the 50 Most Beautiful People.

Tyler dated her Inventing the Abbotts co-star Joaquin Phoenix from 1995 to 1998. While Tyler was in her relationship with Phoenix, she became a vegan. However, after the relationship ended, Tyler went back to eating meat. In 1998, Tyler began dating British musician Royston Langdon of the band Spacehog. They became engaged in February 2001, and married in Barbados on March 25, 2003. In December 2004, she gave birth to a son. On May 8, 2008, the couple confirmed through representatives that they would be separating.

Tyler next appeared in Armageddon (1998), where she played the daughter of Bruce Willis’ character and love interest of Ben Affleck’s character. The film generated mixed reviews, but it was a box office success, earning $553 million worldwide. The movie included the songs “I Don’t Want to Miss a Thing” and “What Kind of Love Are You On” by Aerosmith. In a 2001 interview with The Guardian, she said that she initially turned down the role in Armageddon: “I really didn’t want to do it at first and I turned it down a couple of times, but the biggest reason I changed my mind was because I was scared of it. I wanted to try it for that very reason. I mean, I’m not really in this to do amazing things in my career – I just want it to be special when I make a movie.”

In 2001, Tyler played the object of infatuation for three men (Matt Dillon, John Goodman, and Paul Reiser) in the comedy One Night at McCool’s. She said the role was “definitely the first part where I had to be so physically aware and have people so aware of me physically. Maybe it’s not hard for anybody else, but it is a bit for me. I mean I love my body and I feel very comfortable in my skin but this was tough.” Peter Travers of Rolling Stone wrote: “Tyler, a true beauty, gives the role a valiant try, but her range is too limited to play this amalgam of female perfection.”

In 2001, she starred in the feature film The Lord of the Rings: The Fellowship of the Ring, directed by Peter Jackson. She played the Elf maiden Arwen Undómiel. The film is based on the first volume of J. R. R. Tolkien’s The Lord of the Rings. The filmmakers approached Tyler after seeing her performance in Plunkett & Macleane. She learned to speak the fictitious Elvish language that was created by Tolkien. Mick LaSalle of the San Francisco Chronicle noted that Tyler’s performance was “lovely and earnest”.

A year later, Tyler again starred as Arwen in The Lord of the Rings: The Two Towers, the second installment of the series. The film received favorable reviews. She spent months learning sword fighting for the concluding battle scenes in the film, but her scenes were removed after the script was changed. The film was an enormous box office success, earning over $926 million worldwide and out-grossing its predecessor, which earned over $871 million. In 2003, Tyler featured in the third and last installment of the series, The Lord of the Rings: The Return of the King.

In 2003, she became the spokesperson for Givenchy perfume and cosmetics, and in 2005 the brand named a rose after her, which was used in one of its fragrances. In 2009, she signed on for two more years as Givenchy spokesperson. On December 8, 2011, Givenchy announced a collaboration between Givenchy perfumes and Sony Music. In the video released on February 7, 2012, Tyler covered the INXS song “Need You Tonight”.

Tyler is an active supporter of the charitable United Nations Children’s Fund (UNICEF). She was appointed as a Goodwill Ambassador for the United States in 2003. In November 2004, she hosted the lighting of the UNICEF Snowflake in New York City. She also served as spokesperson for the 2004 Givenchy Mother’s Day promotion, in support of UNICEF’s Maternal and Neonatal Tetanus campaign.

Since 2004, she has donated to the Women’s Cancer Research Fund to support innovative research, education, and outreach directed at the development of more effective approaches to the early diagnosis, treatment, and prevention of all women’s cancers. In October 2007, Tyler, along with her mother, Bebe Buell, and her grandmother Dorothea Johnson, helped launch the Emergen-C Pink energy drink, in which the event was in honor of Breast Cancer Awareness month.

In 2005, she appeared in Steve Buscemi’s independent drama Lonesome Jim, where she was cast alongside Casey Affleck as a single mother and nurse who reconnects with an old fling who has returned to their small Indiana town after a failed run as a novelist in New York. The film was screened at a special presentation at the 2005 Sundance Film Festival where it was nominated for the Grand Jury Prize. Her next appearance was in a supporting role as an insightful therapist who tries to help a once-successful dentist (Adam Sandler) cope with the loss of his family in the September 11 attacks in Reign Over Me (2007).

In 2008, she starred in the home invasion horror film The Strangers with Scott Speedman, a film about a young couple who are terrorized one night by three masked assailants in their remote country house. Although the film garnered a mixed reception among critics, it was a major box office success, earning more than $80 million over its $9 million budget. In an interview with Entertainment Weekly, she said The Strangers was the most challenging role of her career. “It was as far as I could push myself in every way: physically, emotionally, mentally.”

In June 2010, Tyler stated she was “far too sensitive” for casual dates, adding “I fall in love once in a blue moon.”

Tyler appeared in two films released in 2011: Super and The Ledge. In April 2011, publishing house Rodale announced that Tyler and her grandmother Dorothea Johnson, an etiquette expert, had written a book called Modern Manners. It was released October 29, 2013.

Tyler learned transcendental meditation in New York City. In December 2012, she participated in a charity gala for the David Lynch Foundation to provide transcendental meditation to disadvantaged sections of society. At the event, she said, “it helps me make better decisions and be a better mother, and just deal with the daily stress of the modern world that we live in. It helps with everything.”

In 2014, she appeared in Space Station 76, a film directed by Jack Plotnick, also starring Matt Bomer and Patrick Wilson.

In June 2014, Tyler began appearing as a regular in the HBO television series The Leftovers. The series ended after three seasons in 2017.

In 2014, Tyler met David Gardner, a British sports and entertainment manager. They became engaged in July 2015. They have two children together, a son born in February 2015, and a daughter born in July 2016. She later temporarily moved to London shortly after her daughter’s birth.

In 2016, Tyler took on a role opposite Bel Powley in the fantasy/horror drama film Wildling, directed by Fritz Böhm. The film also marks her debut as a producer. It was released in 2018.

In 2017, Tyler quickly landed a role as Anne Vaux in the BBC/HBO miniseries Gunpowder, co-starring Kit Harington. She later joined the second season of the ITV/Hulu period drama series Harlots, starring in a new series regular role as Lady Isabella Fitzwilliam.

In 2019, Tyler co-starred opposite Brad Pitt in the science fiction drama film Ad Astra, which received positive reviews from critics. In 2020, she began a starring role as Michelle Blake in the Fox procedural drama series 9-1-1: Lone Star, which is a spin-off of the drama series 9-1-1. Tyler together with Sean Astin, Sean Bean, Orlando Bloom, Billy Boyd, Ian McKellen, Dominic Monaghan, Viggo Mortensen, Miranda Otto, John Rhys-Davies, Andy Serkis, Karl Urban, and Elijah Wood, plus writer Philippa Boyens and director Peter Jackson on June 1, 2020 joined Josh Gad’s YouTube series Reunited Apart which reunites the cast of popular movies through video-conferencing, and promotes donations to non-profit charities.