O'Donnell began modeling at the age of thirteen and was featured in several commercials.
After the success of Circle of Friends (1995), O'Donnell played Robin in Batman Forever. He reportedly was part of a field of candidates that included Leonardo DiCaprio, Matt Damon, Christian Bale (who later went on to play the Dark Knight himself), Jude Law, Ewan McGregor, Corey Haim, Corey Feldman, Toby Stephens, and Scott Speedman. Producers narrowed their choices to DiCaprio and O'Donnell. At a comic book convention, they asked a group of eleven year-old boys, the target audience, which actor could win a fistfight. After the boys overwhelmingly declared O'Donnell the winner, he was ultimately given the role. By coincidence, O'Donnell was said to be 20th Century Fox's favorite choice to play Jack Dawson in Titanic, but DiCaprio ended up with the role.
O'Donnell followed with a starring role in 1996's The Chamber, based on the John Grisham novel. He subsequently reprised his role in the Batman sequel, Batman & Robin, in 1997. Although a box office success the movie was critically panned and O'Donnell himself has called it a low point in his career. He was considered for the lead role in Spider-Man, when the project was in development with James Cameron directing in 1996. Tobey Maguire was ultimately cast.
O'Donnell did not appear in another movie for two years. He was the producers' original choice for the role of James Edwards in Men in Black (1997), but, after he turned it down, the role went to Will Smith. The Robert Altman film Cookie's Fortune, The Bachelor (1999) and Vertical Limit (2000) were only moderately successful. Following Vertical Limit, a four-year hiatus led some to believe Batman & Robin had damaged his career. However, he came back in 2004 with the widely praised Kinsey.
O'Donnell took a lead role in the Fox Network television series Head Cases in 2005. The show was the first show of the fall 2005 season to be canceled, and only two episodes were aired. He was subsequently cast as veterinarian Finn Dandridge on the ABC drama Grey's Anatomy.
He figured prominently in the TNT miniseries The Company as fictional CIA agent Jack McAuliffe, in a performance which subtly portrayed his character's progression from spoon-fed Yale elitist to jaded, post-Cold War cynic. Film projects for 2008 include Kit Kittredge: An American Girl and Max Payne.
The couple have five children, three sons and two daughters: Lily Anne O'Donnell (b. September 1999), Christopher Eugene O'Donnell Jr (b. October 24, 2000), Charles McHugh O'Donnell (b. July 11, 2003), Finley O'Donnell (b. March 24, 2006), and Maeve Frances O'Donnell (b. December 10, 2007 in Los Angeles).
O'Donnell is an avid golfer. He participated in a golf outing to help raise money for the Motion Picture and Television Fund, for which they raised $500,000 in the year 2000.
| Year | Title | Role | Notes |
|---|---|---|---|
| 1990 | Men Don't Leave | Chris Macauley | |
| 1991 | Fried Green Tomatoes | Buddy Threadgoode | |
| 1992 | School Ties | Chris Reece | |
| Scent of a Woman | Charlie Simms | ||
| 1993 | The Three Musketeers | D'Artagnan | |
| 1994 | Blue Sky | Glenn Johnson | |
| 1995 | Circle of Friends | Jack Foley | |
| Mad Love | Matt Leland | ||
| Batman Forever | Robin/Richard "Dick" Grayson | ||
| 1996 | The Chamber | Adam Hall | |
| In Love and War | Ernest 'Ernie' Hemingway | ||
| 1997 | Batman & Robin | Robin/Richard "Dick" Grayson | |
| 1999 | Cookie's Fortune | Jason Brown | |
| The Bachelor | Jimmie Shannon | ||
| 2000 | Vertical Limit | Peter Garrett | |
| 2002 | 29 Palms | The Hitman | |
| 2003 | The Practice | Brad Stanfield | TV series |
| 2004 | Kinsey | Wardell Pomeroy | |
| 2005 | The Sisters | David Turzin | |
| Head Cases | Jason Payne | TV series | |
| 2007 | Grey's Anatomy | Dr. Finn Dandridge | TV series |
| The Company | Jack McAuliffe | TV miniseries | |
| 2008 | Kit Kittredge: An American Girl | Mr. Kittredge | |
| Max Payne | Jason Colvin | awaiting release | |