As a teenager, O'Donnell started modeling and acting in commercials before landing his first feature film, Men Don't Leave, in 1990. As he made a name for himself in a succession of films in the early '90s, O'Donnell appeared in prestigious projects with seasoned actors, two of whom won Oscars for their work (Al Pacino for Scent of a Woman and Jessica Lange for Blue Sky). Having earned heartthrob status, he took on diverse roles, including parts as a conflicted attorney in The Chamber, a young Ernest Hemingway in the flop In Love and War and Robin in two critically reviled Batman movies. A break in his film career allowed O'Donnell to focus on his personal life, marrying his longtime sweetheart and becoming a father. Turning his attention to the small screen in the 2000s, he revived his career with recurring roles as a murderer on The Practice and as a sexy veterinarian on one of TV's most popular series, Grey's Anatomy. In 2009, he took on the starring role of special undercover agent Callen on the spin-off series NCIS: Los Angeles.
- The youngest of seven children.
- Began modeling at age 13 before appearing in a McDonald's commercial, serving Michael Jordan breakfast.
- While he was in college, Barbra Streisand called him to apologize for giving the role of her son in Prince of Tides (a role originally promised to him) to her own son.
- In 1992, received the Chicago Film Critics Association Award for Most Promising Actor for Scent of a Woman and School Ties.
- In 2001, made his Broadway stage debut in Arthur Miller's The Man Who Had All the Luck.
- Appeared in two episodes of NCIS in 2009 that served as a backdoor pilot for his new spin-off series NCIS: Los Angeles.
- 1993, Golden Globe — Best Performance by an Actor in a Supporting Role in a Motion Picture: Nominee
- Lily Anne O'Donnell — Daughter
- William O'Donnell — Father
- Charles McHugh O'Donnell — Son
- Caroline Fentress — Wife
- Julie O'Donnell — Mother
- Christopher Eugene O'Donnell Jr. — Son
- Finley O'Donnell — Son
- Maeve Frances O'Donnell — Daughter
- Boston College, Boston, Massachusetts, United States (BA in Marketing, 1994); attended University of California, Los Angeles, California, United States
- Birth Name: Christopher Eugene O'Donnell
- Birth Place: Winnetka, Illinois, United States
- Profession: Actor