Tyler dated actor Joaquin Phoenix from 1995 to November 1998; The couple met on the set of Inventing the Abbotts. In 1998, she began dating British musician Royston Langdon of the band Spacehog. The couple became engaged in February 2001, and got married in Barbados on March 25, 2003. On December 14, 2004, she gave birth to a son, Milo William Langdon. On May 8, 2008, Tyler and Langdon confirmed through representatives that they would be separating but remain friends. She lives in New York City. Tyler is a United Nations Children's Fund (UNICEF) Goodwill Ambassador for the United States and was appointed in 2003 in an effort to help save and protect children around the world. In November 2004, she participated in UNICEF's lighting of a Snowflake in New York City. The UNICEF Snowflake serves as a beacon of hope, peace and compassion for vulnerable children around the world. Tyler served as spokesperson for the 2004 Givenchy Mother's Day promotion. For every gift set sold, all proceeds from sales went to UNICEF's Maternal & Neonatal Tetanus (MNT) campaign to save mothers and newborns from tetanus infections.

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. She is good friends with designer Stella McCartney, model Helena Christensen and actresses Kate Hudson and Gwyneth Paltrow. Tyler has stated that she "grew up obsessed with horror movies". She says among her favorite horror movies are Night of the Living Dead (1968), Rosemary's Baby (1968) and The Shining (1980). Tyler is a vegan.

Internationally viewed as a sex symbol, Tyler was chosen by People magazine as one of the "50 Most Beautiful People" in 1997. She was also voted the sixth Sexiest Female Movie Star by Australian Empire magazine in September 2002. Tyler was ranked in Maxim magazine's "Hot 100 List" in 2004, and was ranked in New York magazine's "Most Beautiful New Yorkers" in 2005. In 2003, Tyler became the spokesperson for Givenchy perfume and cosmetics, in 2005 Givenchy named a rose after her, which was used in one of its fragrances.

• The Incredible Hulk (2008) (VG) (voice) .... Betty Ross
• The Incredible Hulk (2008) .... Betty Ross
• The Strangers (2008) .... Kristen McKay
• Smother (2008/II) .... Clare Cooper
• Reign Over Me (2007) .... Angela Oakhurst
• Lonesome Jim (2005) .... Anika
• Jersey Girl (2004) .... Maya
• The Lord of the Rings: The Return of the King (2003) .... Arwen
  ... aka Der Herr der Ringe: Die Rückkehr des Königs (Germany)
  ... aka The Return of the King (USA: short title)
• The Lord of the Rings: The Two Towers (2002) .... Arwen
  ... aka Der Herr der Ringe: Die zwei Türme (Germany)
  ... aka The Two Towers (USA: short title)
• The Lord of the Rings: The Fellowship of the Ring (2001) .... Arwen
  ... aka The Fellowship of the Ring (USA: short title)
  ... aka The Lord of the Rings: The Fellowship of the Ring: The Motion Picture (USA: promotional title)
• One Night at McCool's (2001) .... Jewel Valentine
• Dr T and the Women (2000) .... Marilyn
  ... aka Dr. T and the Women (Germany) (USA: alternative spelling)
  
• Onegin (1999) .... Tatyana Larina
• Cookie's Fortune (1999) .... Emma Duvall
• Plunkett & Macleane (1999) .... Lady Rebecca Gibson
• Armageddon (1998/I) .... Grace Stamper
• Can't Hardly Wait (1998) (voice) (uncredited) .... Gum Girl
• U Turn (1997) .... Girl in Bus Station
  ... aka U Turn - Ici commence l'enfer (France)
• Inventing the Abbotts (1997) .... Pamela Abbott