Filmography
| Year | Title | Role |
| 2026 | Legally Blonde 3 (2023) | Elle Woods |
| 2022 | Where the Crawdads Sing (2022) | Producer |
| 2021 | Sing 2 (2021) | Rosita |
| 2019 | Lucy In The Sky | Producer |
| 2018 | A Wrinkle in Time | Mrs. Whatsit |
| 2018 | This Changes Everything (2019) | Self |
| 2017 | Home Again | Alice |
| 2016 | Chantez | Rosita |
| 2015 | Hot Pursuit | Cooper |
| 2014 | The Good Lie | Carrie Davis |
| 2014 | Gone Girl | Producer |
| 2014 | Wild | Cheryl Strayed |
| 2014 | Inherent Vice | Penny |
| 2013 | Mud | Juniper |
| 2013 | Devil's Knot | Pam Hobbs |
| 2012 | This Means War | Lauren |
| 2011 | Water for Elephants | Marlena |
| 2010 | How Do You Know | Lisa |
| 2009 | Monsters vs. Aliens | Susan Murphy / Ginormica |
| 2008 | Four Christmases | Kate |
| 2007 | Rendition | Isabella El-Ibrahimi |
| 2006 | Penelope | Annie |
| 2005 | Walk the Line | June Carter |
| 2005 | Just Like Heaven | Elizabeth Masterson |
| 2004 | Vanity Fair | Becky Sharp |
| 2003 | Legally Blonde 2: Red, White & Blonde | Elle Woods |
| 2002 | Sweet Home Alabama | Melanie |
| 2002 | The Importance of Being Earnest (2002) | Cecily |
| 2001 | The Trumpet of the Swan | Serena |
| 2001 | Legally Blonde | Elle Woods |
| 2000 | American Psycho (2000) | Evelyn Williams |
| 2000 | Little Nicky | Holly |
| 1999 | Election | Tracy Enid Flick |
| 1999 | Cruel Intentions | Annette Hargrove |
| 1999 | Best Laid Plans | Lissa |
| 1998 | Pleasantville | Jennifer Wagner |
| 1998 | Twilight (1998) | Mel Ames |
| 1996 | Freeway | Vanessa Lutz |
| 1991 | The Man in the Moon | Danielle 'Dani' Trant |
