Early life

O'Donnell was born in Winnetka, Illinois, the son of Julie Ann Rohs von Brecht and William Charles O'Donnell, Sr., a general manager of WBBM-AM, a CBS radio station. He is the youngest of seven children, with four sisters and two brothers, and is of German and Irish descent. He was raised in a Roman Catholic family and attended Roman Catholic schools, including Loyola Academy in Wilmette, Illinois for high school, graduating in 1988. He attended Boston College and graduated with a Bachelor of Science in marketing. He began modeling at the age of 13, and was featured in several commercials.

Career

O'Donnell was discovered when he was cast in a McDonald's commercial, in which he served Michael Jordan. His first television role was an appearance on the series Jack and Mike in 1986. At the age of 17, he was offered a chance to audition for a part in the movie Men Don't Leave, with Jessica Lange, and he won the role. In the early 1990s, O'Donnell was a featured player in many successful movies such as Fried Green Tomatoes (1991), School Ties (1992), and Scent of a Woman (1992) with Al Pacino (receiving a nomination for the Golden Globe Award for Best Supporting Actor, which he lost to Gene Hackman for Unforgiven). He was named one of the 12 Promising New Actors of 1992 in John Willis' Screen World, Vol. 44.

After the success of Blue Sky (1994) and Circle of Friends (1995), O'Donnell played Dick Grayson/Robin in Batman Forever. He reportedly was part of a field of candidates that included Leonardo DiCaprio, Matt Damon, 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 11-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. 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 as Robin 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 also appeared in the 2004 episode of Two and a Half Men entitled "An Old Flame With A New Wick." 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 featured prominently in the TNT miniseries The Company as fictional CIA case officer Jack McAuliffe, in a performance that subtly portrayed his character's progression from spoon-fed Yale elitist to jaded, post-Cold War cynic. Film projects for 2008 included Kit Kittredge: An American Girl and Max Payne.

Since 2009, O'Donnell stars in NCIS: Los Angeles, a spin-off of NCIS, as G. Callen, an NCIS Special Agent in charge of the Office of Special Projects Team stationed in Los Angeles. CBS describes Callen as "a chameleon who transforms himself into whomever he needs to be to infiltrate the criminal underworld."

In 2010, O'Donnell appeared in the sequel to the 2001 movie Cats & Dogs, The Revenge of Kitty Galore.

Personal life

O'Donnell is married to Caroline Fentress. They have five children.

O'Donnell is a practicing Roman Catholic.

Filmography

Film

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	Nominated - Golden Globe Award for Best Supporting Actor
1993	The Three Musketeers	D'Artagnan	Nominated - Razzie Award for Worst Supporting Actor
1994	Blue Sky	Glenn Johnson
1995	Circle of Friends	Jack Foley
	Mad Love	Matt Leland
	Batman Forever	Dick Grayson/Robin
1996	The Chamber	Adam Hall
	In Love and War	Ernest 'Ernie' Hemingway
1997	Batman & Robin	Dick Grayson/Robin	Nominated - Razzie Award for Worst Supporting Actor Nominated - Razzie Award for Worst Screen Couple
1999	Cookie's Fortune	Jason Brown
	The Bachelor	Jimmie Shannon
2000	Vertical Limit	Peter Garrett
2002	29 Palms	The Hitman
2004	Kinsey	Wardell Pomeroy
2005	The Sisters	David Turzin
2008	Kit Kittredge: An American Girl	Jack Kittredge
	Max Payne	Jason Colvin
2010	Cats & Dogs: The Revenge of Kitty Galore	Shane
	A Little Help	Bob

Television

Year	Title	Role	Notes
1986	Jack and Mike	Evan	Episode: Cry Uncle
2003	The Practice	Brad Stanfield	4 episodes
2004	Two and a Half Men	Jill/Bill	Episode: An Old Flame with a New Wick
2005	Head Cases	Jason Payne	2 episodes
2007	Grey's Anatomy	Dr. Finn "McVet" Dandridge	9 episodes
	The Company	Jack McAuliffe	TV miniseries, 6 episodes
2009	NCIS	G. Callen	Episode: "Legend (Parts 1 & 2)"
2009-present	NCIS: Los Angeles		168 episodes
2012	Hawaii Five-0		Crossover episode: "Pa Make Loa"
2013	Who Do You Think You Are?	Himself	Episode:

[ Source: Wikipedia ]