| Year | Title | Role | Notes |
|---|---|---|---|
| 1993 | Leprechaun | Tory Reding | |
| 1996 | She's the One | Renee Fitzpatrick | |
| 1996 | Dream for an Insomniac | Allison | |
| 1997 | 'Til There Was You | Debbie | |
| 1997 | Picture Perfect | Kate Mosley | |
| 1998 | The Thin Pink Line | Clove | |
| 1998 | Waiting for Woody | Herself | Short film |
| 1998 | The Object of My Affection | Nina Borowski | |
| 1999 | Office Space | Joanna | Cult hit |
| 1999 | The Iron Giant | Annie Hughes | Voice only |
| 2001 | Rock Star | Emily Poule | |
| 2002 | The Good Girl | Justine Last | Independent film |
| 2003 | Bruce Almighty | Grace Connelly | |
| 2003 | Abby Singer | Herself | Cameo appearance |
| 2004 | Along Came Polly | Polly Prince | |
| 2005 | Derailed | Lucinda Harris | |
| 2005 | Rumor Has It... | Sarah Huttinger | |
| 2006 | Friends with Money | Olivia | Independent film |
| 2006 | The Break-Up | Brooke Meyers | |
| 2008 | Marley & Me | Jenny Grogan | |
| 2009 | He's Just Not That into You | Beth Murphy | |
| 2009 | Management | Sue Claussen | Independent film. Also Executive Producer |
| 2009 | Love Happens | Eloise Chandler | |
| 2009 | Journey to Sundance | Herself | Documentary |
| 2010 | The Bounty Hunter | Nicole Hurly | |
| 2010 | The Switch | Kassie Larson | Also Executive Producer |
| 2011 | Just Go with It | Katherine Murphy | |
| 2011 | Horrible Bosses | Dr. Julia Harris | |
| 2012 | Wanderlust | Linda |
